Trinidad, JoshChen, LiLian, AngelaZhao, Boxin2017-12-132017-12-132017-10-01http://dx.doi.org/10.1016/j.ijadhadh.2017.06.012http://hdl.handle.net/10012/12707The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.ijadhadh.2017.06.012 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The mechanical bonding strength of electrically conductive adhesives (ECAs), as well as the impact of residual solvent on the bonding strength was investigated between a copper clad FR-4 surface and conductive adhesives using Lap-shear testing. Both solvent-free and solvent-assisted formulations with various filler concentrations of silver (Ag) and sodium dodecyl sulfate (SDS)-decorated graphene (Gr(s)) in epoxy matrices were prepared and compared. It was found that the introduction of 0.75wt% Gr(s) in solvent-free formulations increased the Lap-shear strength (LSS), while the combination of ethanol solvent and SDS in solvent-assisted formulations significantly decreased the LSS. In addition, it was found that increasing the Ag content generally lowers the LSS for both the solvent-free and solvent-assisted formulations. By examining the structure and interface of both formulations using optical microscopy, surface profilometry and SEM, we found that the solvent-assisted formulations exhibit more voids at the surface of the paste and more bubble formation throughout the material compared to the solvent-free formulations. Therefore, the significant drops of LSS in solvent-assisted Gr(s)-filled formulations may be attributed to the formation of bubbles at the micron range during the curing process.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Conductive adhesivesLap-shear strengthSolventSurfactant-decorated grapheneArticle