| 초록 |
Using a low-energy Ar+ ion-beam with and without a reactive gas, poly(tetrafluoro ethylene) (PTFE) films were modified to have special surface features. The surface functional groups of the modified PTFE were confirmed with X-ray photoelectron spectroscopy as increasing various oxygen-containing functional groups. The adhesion strength between the PTFE and the copper was significantly improved. This high adhesion strength is ascribed to both changes in the surface morphology and chemical interactions. The surface modification altered the failure mode from adhesive failure for the unmodified PTFE/Cu interface to cohesive failure for the surface-modified PTFE/Cu layer interface. The low-energy Ar+ ion-beam was also used to modify the surface of a polyetheretherketone (PEEK) dry powder. Surface smoothening occurred so that the surface roughness reached almost constant value after some irradiation time. The incorporation of functional groups on the PEEK surface and the surface topology change had opposite effects on the adhesion strength between PEEK and copper. Dominance of the former was evident because the lap-shear strength initially increased with the irradiation. The special surface features significantly enhanced the adhesion strength between the evaporated copper layer and the modified PEEK surface. However, the decrease in the surface roughness with ion-beam irradiation implies a decrease in adhesion strength due to a smaller contact area, and the shear strength due to topology change also slowly decreased after a long time irradiation. |
