This paper presents part of our research and development results for virtual thermo-mechanical prototyping of electronic packaging. Philips' optimization strategy focuses on the development of reliable Response Surface Models (RSM) for the underlying nonlinear response is demonstrated. This strategy is especially suitable for virtual design prototyping, in which adaptive (sequential) Design Of Experiment (DOE) methodologies are integrated with advanced RSM methods. Once the RSM has satisfied the specified accuracy criteria, design optimization can be conducted efficiently. The demonstrator presented in this paper shows that integration of reliable nonlinear FEM-based simulation models with the Philips optimization method is an effective and efficient method for virtual thermo-mechanical prototyping of electronic packaging.