The escalating demand for high-performance computing is driving the expansion of high-end packages, leading to increased power requirements. Efficient heat dissipation is crucial for maintaining optimal performance and reliability, particularly in complex heterogeneous integration (HI) packages. Thermal Interface Material (TIM) plays a pivotal role in establishing effective heat transfer pathways between electronic components and heat sinks. However, current approaches for TIM characterization and assessment face challenges in accurately reflecting real-world usage conditions, particularly in non-symmetric warpage scenarios.This paper proposes a methodology to bridge the gap between TIM testing and actual usage conditions, focusing on predicting the bond-line thickness (BLT) of second-level TIM during the early stages of package design. Building upon existing research on TIM characterization methods, and numeric approaches, our methodology integrates Digital Image Correlation (DIC) techniques, Finite Element Analysis (FEA), and pressure paper analysis to assess surface warpage, stress distribution, and BLT under varying temperature and loading conditions.By addressing the disparity between TIM testing and usage conditions and offering a predictive approach for BLT determination, this paper contributes to advancing thermal management strategies in heterogeneous integration packages, thereby enhancing performance, reliability, and design efficiency in high-performance computing applications.