Electrically conductive adhesives with sintered silver nanowires

Concerning the hazard to human and environment by lead, the lead-free solders and the electrically conductive adhesives (ECAs) have been considered as the most promising alternatives of the tin-lead solder. Electrically conductive adhesives offer numerous advantages compared to conventional solder technology such as environmental friendliness, mild processing conditions, low stress on the substrates, and fine pitch interconnect capability. It has received considerable attention in microelectronic packaging that the nano-size metal particles fuse at much lower temperature than the melting point of the bulk metal. The sintering of nano-size silver in ECAs can reduce the number of contact points between fillers and increase the conductivity of ECAs. The silver nanowires with a slenderness ratio of 50~60 were successfully synthesized through a polyol process and characterized by field emission scanning electron microscopy (SEM) in this paper. The silver nanowires began to sinter at 200degC and conductive adhesives filled with silver nanowires were studied.