Single Shot of Arf Laser-Induced Photochemical Nucleation of Copper on Polyethylene-Terephthalate Surface

Abstract

ABSTRACTCopper nuclei was grown on a PET surface in the copper sulfate water solution ambience with only one shot of ArF laser.· General electronic circuit printed boards have been made by sticking the copper foils with adhesive agents after having made the foil surface rough. Consequently, even the printed board of low conductivity might generate a high frequency noise due to the difference between the copper foils and adhesive agents. If atoms composing plastics and metal could be combined by a chemical method instead of the conventional physical methods, a hybrid material made of both plastics and metal would be produced.We have reported for the substitution of copper atoms on an all-aromatic-polyimide surface by a single shot of ArF laser irradiation In this study, with one single shot of ArF laser, we succeeded in growing the Cu nuclei on the PET film whose ultraviolet absorption is lower than all-aromatic-polyimide. The sample surface was photo-oxidized with the Xe2 excimer lamp in pre-treatment. A fused silica glass was placed on the sample surface, and the sulfate water solution was poured into the gap between the glass and the sample to form a thin liquid layer. Then, the sample was vertically irradiated once by the circuit patterned ArF laser light with the laser fluence of 28mJ/cm2. The photo-dissociated copper atom formed the C-O-Cu bond with active oxygen to sub stitute on the PET surface. The modified sample was, then, immersed in the electro less plating solution at 60 degrees Celsius for 15 minutes; the copper thin film of about 24mm was grown on the modified surface.