A new method to characterize the thermomechanical response of multilayered structures in power electronics

To record the coefficient of thermal expansion (CTE) of metallized surfaces on Si- substrates with different thickness ratios, a new testing method is introduced. Laseroptical sensors based on the speckle correlation method were applied to determine non-contacting thermal strain values of multilayered structures with high strain resolution. This technique is usually used for the determination of mechanical properties of freestanding foils and wires performing tensile tests. It could be shown, that the thickness of substrate clearly influences the thermal expansion coefficient of the metallization layer.