title: Double-Wall Nanotubes and Graphene Nanoplatelets for Hybrid Conductive Adhesives with Enhanced Thermal and Electrical Conductivity.
abstract: Improving the electrical and thermal properties of conductive adhesives is essential for the fabrication of compact microelectronic and optoelectronic power devices. Here we report on the addition of a commercially available conductive resin with double-wall carbon nanotubes and graphene nanoplatelets that yields simultaneously improved thermal and electrical conductivity. Using isopropanol as a common solvent for the debundling of nanotubes, exfoliation of graphene, and dispersion of the carbon nanostructures in the epoxy resin, we obtain a nanostructured conducting adhesive with thermal conductivity of ∼12 W/mK and resistivity down to 30 μΩ cm at very small loadings (1% w/w for nanotubes and 0.01% w/w for graphene). The low filler content allows one to keep almost unchanged the glass-transition temperature, the viscosity, and the curing parameters. Die shear measurements show that the nanostructured resins fulfill the MIL-STD-883 requirements when bonding gold-metalized SMD components, even after repeated thermal cycling. The same procedure has been validated on a high-conductivity resin characterized by a higher viscosity, on which we have doubled the thermal conductivity and quadrupled the electrical conductivity. Graphene yields better performances with respect to nanotubes in terms of conductivity and filler quantity needed to improve the resin. We have finally applied the nanostructured resins to bond GaN-based high-electron-mobility transistors in power-amplifier circuits. We observe a decrease of the GaN peak and average temperatures of, respectively, ∼30 °C and ∼10 °C, with respect to the pristine resin. The obtained results are important for the fabrication of advanced packaging materials in power electronic and microwave applications and fit the technological roadmap for CNTs, graphene, and hybrid systems.
authors.affiliation: CNR-Istituto per i Processi Chimico-Fisici , Viale F. Stagno D'Alcontres 37, I-98168 Messina, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Messina
authors.affiliation: CNR-Istituto per i Processi Chimico-Fisici , Viale F. Stagno D'Alcontres 37, I-98168 Messina, Italy.
authors.forename: Nancy
authors.initials: N
authors.lastname: Leone
authors.affiliation: CNR-Istituto per i Processi Chimico-Fisici , Viale F. Stagno D'Alcontres 37, I-98168 Messina, Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Foti
authors.affiliation: CNR-Istituto per i Processi Chimico-Fisici , Viale F. Stagno D'Alcontres 37, I-98168 Messina, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Di Marco
authors.affiliation: CNR-ISMN, Area della Ricerca RM1-Montelibretti, Monterotondo Scalo, I-00016 Rome, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Riccucci
authors.affiliation: CNR-ISMN, Area della Ricerca RM1-Montelibretti, Monterotondo Scalo, I-00016 Rome, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Di Carlo
authors.affiliation: Finmeccanica, Via Villagrazia 79, I-90125 Palermo, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Di Maggio
authors.affiliation: Finmeccanica, Via Villagrazia 79, I-90125 Palermo, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Cassata
authors.affiliation: Finmeccanica, Via Villagrazia 79, I-90125 Palermo, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Gargano
authors.affiliation: CNR-Istituto per i Processi Chimico-Fisici , Viale F. Stagno D'Alcontres 37, I-98168 Messina, Italy.
authors.forename: Cristiano
authors.initials: C
authors.lastname: D'Andrea
authors.affiliation: CNR-Istituto per i Processi Chimico-Fisici , Viale F. Stagno D'Alcontres 37, I-98168 Messina, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Fazio
authors.affiliation: CNR-Istituto per i Processi Chimico-Fisici , Viale F. Stagno D'Alcontres 37, I-98168 Messina, Italy.
authors.forename: Onofrio Maria
authors.initials: OM
authors.lastname: Maragò
authors.affiliation: Finmeccanica, Via Villagrazia 79, I-90125 Palermo, Italy.
authors.forename: Benedetto
authors.initials: B
authors.lastname: Robba
authors.affiliation: CNR-Istituto per i Processi Chimico-Fisici , Viale F. Stagno D'Alcontres 37, I-98168 Messina, Italy.
authors.forename: Cirino
authors.initials: C
authors.lastname: Vasi
authors.affiliation: CNR-ISMN, Area della Ricerca RM1-Montelibretti, Monterotondo Scalo, I-00016 Rome, Italy.
authors.forename: Gabriel Maria
authors.initials: GM
authors.lastname: Ingo
authors.affiliation: CNR-Istituto per i Processi Chimico-Fisici , Viale F. Stagno D'Alcontres 37, I-98168 Messina, Italy.
authors.forename: Pietro Giuseppe
authors.initials: PG
authors.lastname: Gucciardi
keywords: chip bonding; conductive epoxy; electrical conductivity; graphene; liquid-phase exfoliation; nanotubes; thermal conductivity; thermal interface materials