Topografy and Characterization of Surface Treated Polyethylene(terephthalate) Films Used in Flexible Circuits Fabrication.

V L S SERVERGNINI; S C DOMENECH; V SOLDI; V DRAGO; ENIO LIMA JR.; N G BORGES JR.; A O V AVILA

Florianópolis, Brasil

Congreso; The Polymers Processing Society America Regional Meething, PPS 2004; 2004

Excellent mechanical and electric performance are important characteristics for the production of flexible electrical circuits used in pressure sensors. The fabrication of these circuits consist in deposit a Ni-P alloy on poly(ethylene therephthalate) (PET) films by electroless. Studies on the optimization of the Ni-P deposition process indicated that acid etching time is an important factor influencing the adherence stregth of the Ni-P alloy on the polymeric surface. Considering the extremely oxidant character of the reagent employed in the surface treatment, a study focused on the effect of the etching time on the properties of the PET films and on the adhesion strength of the Ni-P/PET couple was carried out. PET films were submitted at different acid etching times and analyzed by Contact Angle measurements, Atomic Force Microscopy, Scanning Electron Microscopy and Fourier-Transformed Infrared Spectroscopy (FTIR). It was verified that the acid etching time in which the highest values of adherence strength were obtained is approximately 60 min. Contact angle measurements indicated that the hydrophilic character of the polymer surface increase with acid etching time, reach a maximum at 60 min and decrease at longer times. Morphological analysis demonstrate that nano-scaled roughness formed at theoptimal acid etching time is also responsible for the anchorage Ni-P alloy at the polymer surface. The FTIR spectra showed that the chemical treatment affects only superficial layers and other properties of the polymeric substrate are not altered.