Effect of Plasma Treatments and Plasma-Polymerized Films on the Adhesion of Parylene-C to Substrates

This work deals with the most severe limitations of Parylene-C coatings, namely their poor adhesion to the substrate and barrier properties. To address these limitations, the surface properties of the substrate are modified prior to the Parylene deposition step by depositing a nano-film interfacial layer by means of a plasma polymerization process. The multilayer coating was realized using a newly designed, innovative multi-chamber system. Tests of dry adhesion (at 90 degrees and 180 degrees) and electrochemical impedance spectroscopic (EIS) measurements were performed to evaluate the effect of the plasma pre-processing. Adhesion strength of 3 and 6.8Ncm(-1) were recorded for the 90 degrees and 180 degrees tape tests, respectively, while an impedance level of 10(7)cm(-2) at 100Hz was registered by EIS measurement.