Bonding of polymer and glass using nano-adhesion layer for flexible electronics

This study addresses a sealing method for flexible polymer substrate. A modified method of the surface activated bonding (SAB) is applied to bonding polymer films together and polymer film to glass wafer. Void-free bonding can be achieved at optimized bonding conditions in which surfaces to bond are smooth. Moreover, the bond interface is enough strong to bend without break. The adhesion strength of the bonded samples is so strong that fracture occurs in the polymer bulk rather than at the bond interface during a peeling test. Investigations of the bonded samples by transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR) reveal that bonding is achieved by chemical interactions between the polymer surface and deposited atoms. Also, bonding of polymer substrates coated with Al₂O₃ gas-barrier layer was performed. The gas barrier layer was deposited via Atomic layer deposition (ALD), which is reported to achieve dense deposited layer with high gas barrier property. Surfaces of the Al₂O₃ gas barrier layers on polymer film were successfully bonded by the above-mentioned method.