Characterization and Reliability of Paste Based Thin-Film Sn-Cu TLPS Joints for High Temperature Power Electronics Electro-mobility plays an important role in addressing the fuel efficiency and emission requirements, as well as the market demands for low operational costs. Power electronics which is a key technology in electro-mobility motivates the present work. This paper gives an overview of the optimization of the present state-of-the-art soldering technologies for diffusion soldering in power electronics, in particular for Transient Liquid Phase Soldering (TLPS) capable of producing die-attach interconnections with remelt temperatures >400deg C. The material characterization and reliability analysis of this thin-film Sn-Cu paste-based TLPS technology is discussed. For demonstration purposes, power modules had been constructed with solder pastes developed for TLPS process. High temperature shear tests up to 500deg C and accelerated reliability tests have been performed to explain the possible microstructural defects and failure modes.