Thiol based chemical treatment as adhesion promoter for Cu-epoxy interface

The paper focuses on the use of thiol as adhesion promoter in Cu-epoxy interface. A parametric study on the thiol deposition procedure for Cu-epoxy system was conducted. Thiol concentration and deposition time was found to be important parameter in adhesion. Low concentrated solution leads to insufficient morphological modification while prolong treatment time results in fracture happened along weak boundary layer. The optimum condition for surface treatment with the current thiol was 5 mM solution for 10 hours. With this thiol treatment, adhesion which was given as fracture toughness has increased from 4.8 Jm^-2 for the untreated sample to 159 Jm^-2. The 30 times adhesion improvement was related to presence of nanostructure upon thiol modification. Both the chemical bonding and morphological changes was found contributes to adhesion.