Moving towards an electrified world requires ultra-high-density power converters. With the adoption of wide-bandgap semiconductors (e.g., SiC, GaN), the next-generation power converters are on the horizon. However, the complexity of compact and high-speed converters is beyond the current industry-standard design flow based on manual and iterative steps. Therefore, research on design automation and optimization has been identified as an emerging topic in the power electronics society. Among different components of the converter, the physical design of power modules has proven critical for achieving high power density and energy efficiency. We present the latest design automation flow for high-density (2D/2.5D/3D) and heterogeneous multi-chip power modules (MCPM) through PowerSynth 2 framework. In this work, we further demonstrate electro-thermal optimization for State-of-the-Art (SOTA) 3D packaging technologies. Using the latest PowerSynth 2 framework, electro-thermal design optimization is carried out on a sample 3D MCPM layout using both exhaustive and evolutionary search methods. The optimized design is hardware-validated against physical measurements. The measurement result has shown an order of magnitude productivity improvement within 10% accuracy compared to the SOTA industry design flow.