Low temperature transient liquid phase bonded Cu-Sn-Mo and Cu-Sn-Ag-Mo interconnects - A novel approach for hybrid metal baseplates

Transient liquid phase (TLP) bonding is one of novel techniques, which is an alternative to conventional soldering used in power electronics packaging. In this paper, we report on the formation and analysis of TLP bonded Cu-Sn-Mo and Cu-Sn-Ag-Mo systems for production of hybrid metal baseplates. The obtained bonds of inter metallic compounds are characterised by shear testing, optical microscopy and energy dispersive X-ray spectroscopy. Cu-Sn-Mo systems show low bond strength due to severe void and crack formation while Cu-Sn-Ag-Mo interfaces demonstrate high homogeneity and considerable shear strength. Thus, it is concluded that the low temperature TLP bonding using Cu-Sn-Ag-Mo can be a promising candidate for the fabrication of hybrid Cu-Mo baseplates. However, deeper studies of thermal reliability of these systems are required.