THE POLYIMIDE (PMDA/ODA)-TITANIUM INTERFACE .1. UNTREATED PMDA/ODA - AN XPS, AES, AFM AND RAMAN-STUDY

The interface between evaporated titanium and PMDA/ODA (pyromellitic dianhydride oxidianiline) polyimide is examined using several techniques: X-ray photoelectron spectroscopy, Auger spectroscopy, atomic force microscopy (AFM), Raman spectroscopy and peel strength measurements. The formation of small TiO2 particles at this interface (15-40 mu m diameter, about 30 nm thickness, covering about 6% of the interfacial area) is demonstrated. The failure is of cohesive type in the polymer layer. When the residual pressure during titanium evaporation is increased, the number of TiO2 particles increases, adhesion of the titanium layer is lowered and the locus of failure is closer to the metal layer.