A phenomenological study of a Sn–Ag–Al composite solder reinforced with Mg–MWCNT: Improved electrical conductivity and thermo-physical performance. (15th February 2018)

• Record Type: Journal Article
• Authors: Kim, Sang Hoon; Choi, Joon-Phil; Eom, Yeong-seong; Nam, Younggyun; Baek, Seonghyeon; Aranas, Clodualdo
• Is Part Of: Materials & design. Volume 140(2018)
• Page Start: 196
• Page End: 208
• Publication Date: 2018-02-15
• Subjects: Composite -- Solder alloy -- Reinforcement -- Powder metallurgy -- Wettability; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2017.11.073
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: A Sn–Ag–Al composite solder alloy reinforced with Mg–multi-walled carbon nanotubes (MWCNT) was prepared using a powder metallurgy (P/M) method. The electrical resistivity of the Sn–Ag–Al–Mg–MWCNT composite solder alloy decreased to 21.91 × 10 − 6 Ω·cm when the Sn–Ag–Al conventional solder alloy (36.15 × 10 − 6 Ω·cm) was reinforced with 2.87 wt% Mg and 0.60 wt% MWCNT (3.47 wt% Mg–MWCNT). The reinforcement by the Mg–MWCNT also provided relatively lower density (6.53 g/cm 3 ) to the composite solder alloy compared to the conventional solder alloy (7.34 g/cm 3 ). The onset melting temperature of the quinary solder alloy was 204.2 °C, which was 10.0 °C lower than that of the ternary solder alloy at 214.2 °C. The wettability of the composite solder powders after reflow on the quartz substrate was increased due to the improved solder fluidity aided by the MWCNT bundle. The improved electrical and thermo-physical performance was induced by a combination of interactions driven by ionic and covalent bonds between the Mg atoms and the MWCNT, and by intermetallic compound formation between the Mg atoms and the other solder constituents. Graphical abstract: A Sn–Ag–Al composite solder alloy reinforced with Mg–MWCNT was found to exhibit higher electrical conductivity, lower density and melting temperature, and better wetting behavior than a Sn–Ag–Al conventional solder alloy. Thus, the Sn–Ag–Al–Mg–MWCNT composite solder bumps were more suitable for interconnection applications than the Sn–Ag–Al conventional solder bumps. Image 2 Highlights: A Sn–Ag–Al conventional solder alloy is reinforced with Mg–MWCNT. Mg is used as a bridging material between the MWCNT and the solder constituents. The novel composite solder alloy exhibits lowered electrical resistivity. The Mg–MWCNT imparts lower density and melting point to the composite solder alloy. The composite solder has superior wettability compared to the conventional solder.