A high-temperature-resistant bond withstanding up to 415 degrees C for SiC power devices is realized at 260 degrees C with a Cu/Sn powder paste and an electroless nickel plated Si3N4/Cu circuit substrate. The bond was formed by using transient liquid phase sintering (TLPS). The bond strength tested at 300 degrees C increases with increasing aging time at 300 degrees C, from the original 40 MPa to 50 MPa after aging at 300 degrees C for 200 h. This is attributed to phase transformation from Cu6Sn5 formed during TLPS to Cu3Sn in the bond during aging. We observed an eta-(Cu,Ni)(6.26)Sn-5 phase at the interface between the TLPS Cu-Sn bond and Ni(P) layer. The interface between the TLPS Cu-Sn bond and Si3N4/Cu/Ni(P)/Ag substrate exhibits very high stability, characterized by a very slow Ni(P) layer consumption rate and Ni3P growth rate. The TLPS Cu-Sn bond on a 5 mu m-thick electroless plated nickel layer is expected to have a life time beyond 10(5) h during storage at 300 degrees C. (C) 2013 The Electrochemical Society. All rights reserved.