A study of mechanical and thermal properties of materials in electronic packaging: application of micro DIC

The mechanical and thermal properties of materials used in electronic packaging are of significant importance. This paper presents a novel application of Digital Image Correlation (DIC) to characterise the properties of polymeric films and solder joints used in electronic packaging. A miniature loading frame and a thermal chamber were designed to load the film and solder samples, respectively. The mechanical properties (Elastic Modulus and Poisson's ratio) of the polymeric film were estimated under uniaxial tension, while the thermal expansion of a solder ball was evaluated in a temperature chamber. Digital images of the samples were documented with a microscopic imaging system and DIC was used to evaluate the in-plane deformation. An algorithm that combined the subpixel technique, displacement fitting and correction of lens aberration was developed to improve the precision of the measurements. Results show that micro DIC is an easy-to-use technique and has strong potential as a characterisation methodology for materials and structures in electronic packaging.