Integration of passives into boards requires research in process steps, material synthesis and characterization, thermomechanical-electrical modeling, fabrication and reliability testing. The literature available on the thenno-mechanical reliability of integral passives and its relation to system level reliability is limited. Reliability of integral passives under thermal excursions through physics based models is presented in this paper. The thenno-mechanical failure mechanisms and their influence on system electrical parameters (R, L and C parameters) are discussed.