Geometric measurement method of Poisson's ratio and Young's elastic modulus of thin film material

Abstract

The invention discloses a geometric measurement method of Poisson's ratio and Young's elastic modulus of a thin film material, the periphery of the thin film material to be detected is clamped for leading the thin film material to form a circular thin film with the radius of a and the clamped periphery, evenly distributed loads q are imposed on the circular thin film, the deflection value w(r) ofany two points on the circular thin film is measured, a calculation expression formula of the Poisson's ratio and the Young's elastic modulus of the thin film is deducted according to the accurate analytical solutions which are given out by Hencky of the circular thin film with the clamped periphery under the action of the evenly distributed loads, and the Poisson's ratio and the Young's elastic modulus of the thin film can be accurately calculated by utilizing the deflection value ratio of any two points on the circular thin film. The geometric measurement method of the Poisson's ratio and the Young's elastic modulus of the thin film has the advantages of simple and feasible operation, few measurement parameters, more accurate solved Poisson's ratio and the Young's elastic modulus and definite mechanical and physical significances.

Description

technical field [0001] The invention relates to a method for measuring Poisson's ratio and Young's elastic modulus of a film material, in particular to a geometric measurement method for the Poisson's ratio and Young's elastic modulus of a film material. Background technique [0002] Thin-film technology has been widely used in many fields, such as protective coatings, decorative coatings, and thin-film devices in the microelectronics industry and optoelectronics industry. Poisson's ratio v and Young's modulus of elasticity E are the two most important characteristics of the film, which determine the mechanical properties and performance of the film. Therefore, the measurement accuracy of Poisson's ratio and Young's modulus of elasticity and the correctness of the measurement method are crucial to the application of thin film technology, and it is also a challenging research topic. In recent years, many scholars have paid a lot of attention, and have invented many technique...

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Problems solved by technology

In addition, some methods can only measure the two-dimensional elastic modulus, namely or The main reason for the difficulty in the measurement work is that it is difficult to obtain accurate analytical solutions for the thin film structure, most of which are numerical solutions, so that the above methods have to introduce too many assumptions in order to obtain an analytical expression for measurement

Although the use of some complex advanced technologies and equipment (such as X-ray diffraction technology, resonance superfrequency spectroscopy technology, laser equipment, acoustic microscope, etc.) will help to improve the measurement accuracy, but because the elastic coefficient of the material usually has a size effect, that is It is related to the size of the material, so if the analytical expression used for the measurement is not derived from the exact analytical solution of the thin film structure, or some unnecessary assumptions are used too much, the accuracy and correctness of the measurement results will also be affected. Still difficult to guarantee, that is, difficult to prove that the measured results are correct

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