Nano-Cu paste sintering in Pt-catalyzed formic acid vapor for Cu bonding at a low temperature

A low temperature all-Cu bonding via the sintering of nano-Cu paste in Pt-catalyzed formic acid vapor was studied, which was demonstrated with a large tolerance of surface oxidation. The bonding strength of oxidized-Cu to Cu could be significantly improved via the treatment of Pt-catalyzed formic acid vapor. The interfacial analysis was carried out to understand the mechanisms.