Effects of the Nanoporous Cu Interlayer on the Bonding Area and Strength for Applications in Packaging of High Power Devices

In this research, we present a promising thermal interface material (TIM) fabricated by nanoporous and nanotwinned structure. By electroplating a nanoporous copper (NP-Cu) interlayer, seamless bonding can be accomplished under 250°C for 30 minutes. The bonding strength between NP-Cu and regular copper (Reg-Cu) reaches 18.02 MPa, comparable to the bonding strength observed with nanotwinned copper (NT-Cu). Both NP-Cu and NT -Cu facilitates the bonding of SiC substrates with rough copper substrates. After bonding at 250°C for 30 minutes followed by furnace cooling, the strength can reach 17.27 MPa. Consequently, NP-Cu has the potential to be one of the options for TIM.