Real-time test device for mechanical properties of film

Abstract

The invention provides a real-time test device for mechanical properties of a film, belonging to the technical field of the test for optical measuring mechanical properties and material mechanical properties. The test device mainly comprises a laser deflection measuring part, a pressure loading part and a film clamping structure. In the test process, the pressure loading is realized by driving a cylinder by a stepping motor, the film is bulged to deform, and meanwhile, a michelson laser interference principle is utilized to measure the deflection of the film. A pressure sensor and a silicon solar cell are utilized to respectively detect the pressure and the deflection. A programmable device FPGA is used for realizing the stepping motor control, data collection and upper computer communication. The upper computer is used for realizing the data display and processing. An optical measuring technique is combined with a film bulging method according to the invention, so that the mechanical properties of the film can be tested and the device is suitable for an elastic plastic film with a certain reflectance on the surface.

Description

technical field [0001] The invention combines the optical measurement technology and the principle of the tympanic membrane method to provide a real-time test device for the mechanical properties of thin films, which belongs to the technical fields of optical measurement mechanics and material mechanical properties testing. Background technique [0002] Thin film is a semiconductor material with excellent mechanical, optical, thermal and electrical properties, which creates conditions for the integration and miniaturization of micro-nano electromechanical system devices. Often used as light-emitting diodes, field effect transistors, protective layers, solar cells and other occasions. Linear one-dimensional and planar two-dimensional suspended thin-film structures are important components of micro-nano electromechanical systems. Testing and improving the mechanical properties of thin-film materials such as elastic modulus and residual stress is the key to improving the stabil...

AI Technical Summary

Problems solved by technology

[0003] The test methods for the mechanical properties of films mainly include tensile method, nano-indentation method, tympanic membrane method, etc. The disadvantage of the stretching method is that it is difficult to overcome the influence of the clamping end, and the film is easily damaged during installation; the nano-indentation method is difficult to overcome the substrate The impact on the mechanical properties of the film is difficult to obtain accurate test results; the tympanic membrane method has a simple principle and high measurement accuracy, which overcomes the shortcomings of the above two methods, and can simultaneously measure multiple parameters, including the elastic modulus and residual stress of the film Wait

[0004] Chinese patent CN106198206A proposes to use the digital speckle correlation method to measure the mechanical properties of the film. During the test, the speckle image needs to be image-processed, the operation is complicated and delayed, and the corresponding relationship between the obtained deflection value and the pressure value is not good; the deflection value is determined by The in-plane displacement is converted from the projection angle, and it is difficult to accurately control the angle value during the test; in order to obtain a better speckle pattern, it is necessary to spray paint on the surface of the film. The thickness of the film is at the micron level or even smaller, and the coating may Performance, the problems mentioned above, the accuracy of the test results of this device is difficult to guarantee

[0005] Negger et al. proposed a micro-scale tympanic membrane test plan in the Journal of Experimental Mechanics in 2014, using a confocal optical microscope combined with a digital image correlation method to measure the three-dimensional deformation of the film. The disadvantage is that the film is prepared by micro-processing technology. complicated process

In 2014, Berdova et al. proposed a rod-type tympanic membrane test method to measure the mechanical properties of nano-alumina films in the journal Acta Materialia. This method has the disadvantages of complex film preparation process and small application range.

Images