As modern technology advances, the demand for compact and complex electronic components has increased, bringing new challenges in managing heat generation within integrated circuits (ICs). Effective thermal management has become essential, as excess heat can impair performance and reduce the operational lifespan of components through thermal wear. In high-stakes applications like electric vehicle (EV) inverters, accurate temperature estimation is vital for efficiency and reliability. This thesis addresses these needs by developing a mathematical thermal model to estimate the junction temperature of MOSFET transistors in EV inverters, utilizing both simplified and complex modeling methodologies with a case study provided by Ideas & Motion Torino.