Effect of multi-walled carbon nanotube (MWCNT) concentration on thermomechanical reliability of MWCNT-reinforced solderable isotropic polymer nanocomposites

Multi-walled carbon nanotube (MWCNT)-reinforced solderable isotropic polymer nanocomposites (SIPNs) containing low-melting-point alloys (LMPAs) were developed to enhance the interconnection properties of solderable isotropic polymer composites (SIPCs). In this study, the reliability properties of MWCNT-reinforced SIPN assemblies with different MWCNT concentrations were investigated through thermal shock (−55–125 °C, 1000 cycles) and high-temperature and high-humidity (85 °C, 85 %RH, 1000 h) tests. In addition, the interfacial microstructure and fracture mode of the MWCNT-reinforced SIPN joint were investigated. All the MWCNT-reinforced SIPN assemblies, with different MWCNT concentrations, showed stable electrical reliability during reliability tests owing to the formation of a metallurgical interconnection between the corresponding metallization layers by molten LMPA fillers. The mechanical reliability properties of all the MWCNT-reinforced SIPN assemblies degraded owing to excessive intermetallic compound (IMC) layer growth. However, the mechanical reliability properties of MWCNT-reinforced SIPNs with a low MWCNT concentration (<1 wt%) were superior to those of the SIPNs without MWCNTs owing to the initial high bonding strength of the former due to the reinforcing effect of MWCNTs.