This study deals with the challenge of warpage in power modules, vital components in the rapidly expanding electric and hybrid-electric vehicle industry. The variations in temperature during manufacturing, resulting in significant warpage changes, contribute to device cracks, delamination, and reduced reliability. The primary focus is understanding and mitigating the warpage phenomenon in power module substrates. This warpage is induced by thermo-mechanical stresses during the assembly packaging process. The investigation begins by exploring the cause of warpage change by characterizing annealed copper properties and employing 2D finite element model (FEM) analysis. The study identifies plastic strain as the dominant cause of warpage change during process steps. Subsequently, a validated 3D FEM simulation model is developed to replicate practical annealing and sintering processes. Lastly, the project delves into factor analysis to identify critical variables influencing warpage. It underscores that balancing residual copper volume is crucial in warpage reduction. Additive and subtractive manufacturing techniques establish a correlation between the removal of copper volume and warpage reduction. This project provides comprehensive insights into the manufacturing process of AMB substrate, warpage behavior, and effective strategies for reduction, constructing a solid foundation for future manufacturing and design.