The electronic packages has progressed smaller from technological improvements and reduced costs in every year. These packages consist of various materials. The problems occur by complex thermal stress which influences small cracks and the interface debonding because of different thermal expansion coefficients. Finite element simulation, used as a standard tool to analyze thermo-mechanical behavior of electronic packages, can suffer from unreliable input data. In this study, the thermal expansion of electronic packages is measured by digital image correlation (DIC). A heating chamber is designed for applying thermal load and DIC provides the full-field thermal deformation fields of the test electronic packages due to temperature changes. The in-plane strain measured by DIC is influenced by the out of plane deformation. By measuring the thermal expansion of the different coefficient materials at same time, the out of plane deformation is corrected. The origin of the fracture is investigated to increase the reliability of the packages structure measuring strain distributions using DIC.