Liquid Paste Interconnects on a Silicon Power Diode

Abstract

State-of-the-art power semiconductors use solid metal interconnects such as wire-bonding, soldering, and sintering. Thermo-mechanical stress degrades these solid metal interconnects and is the main cause of failure in power semiconductors. This letter demonstrates the use of liquid-metals (LMs), which are inherently resistant to thermo-mechanical stress, to package a silicon power diode. The manufacturing process is performed below $80~^{\circ }$ C. The thermo-mechanical lifetime is assessed through power cycling and is shown to increase by factor of 3.3x in comparison to SAC305 solder and aluminum wirebonded diodes. In addition, the thermal resistance of LM packaged diodes shows a 9% improvement. Corrosion and pump out of the LM is thought to be the failure mode.