Reverse Engineering of Thermomechanical Properties for Materials in Microelectronic Packaging

Measuring thermomechanical material properties of electronic components or substrates can be challenging due to its dimensions, multitude in different materials and mutual influences of each other. Knowing these properties however, is crucial for numerical simulations. We propose an optimization workflow that integrates out-of-plane displacement measurements under varying temperatures with simulations to identify the missing material parameters effectively. The proposed workflow is demonstrated on a theoretical example with simulated target values. It is shown that it is possible to find thermomechanical material parameters only from out-of-plane displacement information. The same workflow is also demonstrated on real insulated metal substrate samples, successfully determining the coefficients of thermal expansion, even when increasing the complexity and including the glass transition temperature within the tested temperature range.