Transience of plasma surface modification as an adhesion promoter for polychlorotrifluorethylene

Abstract

Articles you may be interested inPoly͑chlorotrifluoroethylene͒ ͑PCTFE͒ and other fluoropolymers are increasingly used as inner layer dielectrics. However, these polymers have low surface energies and correspondingly poor adhesive properties. Results are presented on the use of a low-pressure ammonia plasma to enhance the surface bondability of PCTFE. The plasma modified PCTFE film surfaces were characterized by x-ray photoelectron spectroscopy and contact angle measurements. Surface modified films exhibited improved adhesion to electroless copper deposits ͑180°peel test͒ compared to coated PCTFE controls and that underwent no plasma exposure. Annealing studies were conducted between 30 and 100°C to examine the stability of the plasma-modified surfaces. For samples annealed below T g , contact angle measurements indicated that the plasma-introduced groups remained bound on the surface for four weeks. For specimens annealed above T g , the surface functionalities were absorbed within the bulk and surface rearrangement occurred within 10 h of annealing time. As a result of rearrangement, the benefit of adhesion enhancement by plasma is lost and the adhesion to copper is reduced.

Surface Modification of Fluororubber Using Atmospheric Pressure Dielectric Barrier Discharge (DBD)

“…5 shows a comparison of the binding energy of C 1s between the untreated F 2311 surface and the plasma-treated surface. The small peak on the low binding energy side of the observed surface decreased, showing a decreased proportion of CH 2 in comparison [4,6,20] . The additional peak C4 at 289.3 to 289.8 was possibly due to CHF−CHF−CHF, CF 2 −CHF−CF 2 and O-C=O groups [4,21] .…”

“…After plasma treatment, the observed C 1s spectra could not be fitted well unless an additional peak was introduced. The component C1 at 286.1 eV to 286.6, eV was assigned to -CH 2 -CF 2 −, CHF−CH 2 −CHF and O-CH 2 group; the component C 2 at 290.4 eV to 291 eV was assigned to CF2-CFCl−CF 2 and CFH−CFCl−CFH groups; the component C3 at 291.9 to 292.3 eV was assigned to CH 2 -CF 2 −CFCl, respectively[4,6,20] . The additional peak C4 at 289.3 to 289.8 was possibly due to CHF−CHF−CHF, CF 2 −CHF−CF 2 and O-C=O groups[4,21] .…”