LIME: Liquid Metal for Semiconductors

Almost all state-of-the-art power semiconductors use solid metal interconnects to connect the chip to other circuit components. Thermo-mechanical stress degrades solid metal interconnects and is the main cause of failure in power semiconductors. This paper uses liquid metals (LIME), which are inherently resistant to thermo-mechanical stress, to replace these interconnects. Preliminary results show that LIME increases the lifetime of power semiconductors by a factor of 80. This facilitates the miniaturization of power electronics, and both the cost and weight of power electronic systems can be reduced by up to 90%. Several iterations of liquid metal packages are shown, using both Silicon and Silicon Carbide chips. In the final iteration reported in this abstract, no solid interconnections remain within the module. Furthermore, the junction-to-ambient thermal resistance is improved by up to 10% using LIME in comparison to SAC305 solder and Aluminium wirebonds.