Influential parameters in the development of Transient Liquid Phase Soldering (TLPS) as a new interconnect system for high power lighting applications

This paper gives an overview on Transient Liquid-Phase Soldering (TLPS) as a new interconnect system for lighting components at package as well as chip level, where the conventional electronic production processes have been optimized for being capable of producing highly durable pore-free TLPS bonds. The growth of intermetallic phases with control of temperature, time and pressure has been investigated in production perspective. The samples processed under optimized over-pressure reflow soldering along with realization of thin solder layers down to less than 15 μm are demonstrated. As a result, TLPS joints with <; 3 % voids with fully grown Sn-Cu intermetallic phases have been realized. Formations of intermetallic phase (IMP) with changes in soldering profile, solder paste height, chip metallization and substrate roughness are discussed.