Elastic Moduli of Electrodeposited Metal Thin Films Measured by Digital Image Correlation Method

Young’s modulus and Poisson’s ratio of electrodeposited metal thin films were calculated by applying the digital image correlation technique. The microstructure of copper thin films was also analyzed by using the electron backscatter diffraction method. First, a program that can calculate sub-pixel displacement was created and a precision stage was used to check its accuracy. Next, tension tests were performed on two metal plates and the program was used to calculate the elastic moduli of the plate materials. The validity of the results was confirmed by comparing the results with those obtained with an electrical strain gage. Finally, the elastic moduli of electrodeposited copper and nickel films were calculated in the same manner. It was clarified that the Young’s modulus of the metal thin films was quite small compared with that of the bulk materials. This result is likely due to the difference in microstructure between bulk materials and electrodeposited thin films.