Low Temperature Direct Bonding between PEEK (Polyetheretherketone) and Pt via Vapor-Assisted Vacuum Ultraviolet Surface Modification

Direct bonding between PEEK (polyetheretherketone) and Pt was achieved at 150 C via a vapor-assisted VUV (vacuum ultraviolet) surface modification method. X-ray photoelectron spectroscopy confirmed that the PEEK and Pt outer surfaces were modified with hydrate bridge layers. A model calculation of gas content during VUV irradiation suggested that the water vapor molar concentration should be optimized to no more than 0.088 mol/m 3 . The strain energy release rate calculation indicated that the energy required to debond the PEEK-Pt interface reached 270 mN/m, which was higher than the energy required to break the bulk PEEK (42 mN/m). SEM observation of fractured PEEK-Pt bonding agreed well with the calculation result that the fracture occurred within PEEK substrate. Thus, the PEEK-Pt bonding was considered strong enough. This technology is expected to be applied in biomedical MEMS applications.