Direct Stress-Strain Measurements from Bulged Membranes Using Topography Image Correlation

Jan Neggers (1) , Johan Hoenagels (1) , François Hild (2) , Stéphane Roux (2) , Marc Geers (1)

1 Department of Mechanical Engineering [Eindhoven]
2 LMT - Laboratoire de Mécanique et Technologie

This paper discusses an experimental method to characterize thin lms as they are encountered in micro-electronic devices. The method enables the measurement of the stress and strain of pressure deflected bulged membranes without using a priori defi ned bulge equations. An enrichment to the Global Digital Image Correlation method is detailed to capture the membrane strain and curvature while robustly dealing with acquisition noise. The accuracy of the method is analyzed and compared to the standard bulge test method. The method is applied to a proof of principle experiment to investigate its applicability and accuracy. Additionally, it is shown for two experimental cases that the method provides accurate results, although the bulge equations do not hold.

Mots clés: strain; stress; digital image correlation; surface pro lometry; thin fi lm; membrane; full-fi eld measurement

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Jan Neggers, Johan Hoenagels, François Hild, Stéphane Roux, Marc Geers. Direct Stress-Strain Measurements from Bulged Membranes Using Topography Image Correlation. Experimental Mechanics, 2014, 54 (5), pp.717-727. ⟨hal-01003511⟩