Jonas Zürcher, Luca Del Carro, et al.
ECTC 2016
The introduction of wide-band-gap semiconductors such as silicon carbide (SiC) in power electronic devices has allowed operation temperatures beyond 300°C. However, these high operational temperatures are not suitable for traditional die-attach materials such as solder. Therefore, a bonding material that is stable beyond 300°C, with high electrical and thermal conductivities and low cost is essential. In this regard, copper (Cu) nanoparticle-based pastes are promising candidates due to their stability at high temperatures and elevated thermal and electrical conductivities. Furthermore, the recent introduction of oxide-free Cu pastes based on amine-passivated Cu nanoparticles enables these materials to be processed in inert atmosphere.We report here on attaching SiC dies to direct-bonded copper ceramic substrates by sintering oxide-free Cu pastes. Applying bonding pressure during sintering improves the die-attach quality by reducing the percentage of residual voids and increasing shear strength. We succeeded in further reducing the percentage of voids by using a paste containing a solvent with a low boiling point and high vapor pressure. Furthermore, we developed a novel dual-layer process to deposit Cu paste that yields residual percentages of voids in the die attach as low as 5% and a shear strength of 29 MPa. Finally, the reliability of the die attach by oxide-free Cu paste was investigated with thermal shock cycling.
Jonas Zürcher, Luca Del Carro, et al.
ECTC 2016
Luca Del Carro, Jonas Zuercher, et al.
ECTC 2017
Feifei Qin, Ali Mazloomi Moqaddam, et al.
Physical Review E
Luca Del Carro, Martin Kossatz, et al.
ECTC 2018