Dupont KK: new method will speed up plasma panel making

DuPont KK, the Japanese subsidiary of US chemical major E.I. du Pont de Nemours and Co., has developed a technique which could cut the cost of plasma flat screens.
The company has found a new way to …

DuPont KK, the Japanese subsidiary of US chemical major E.I. du Pont de Nemours and Co., has developed a technique which could cut the cost of plasma flat screens. The company has found a new way to fabricate circuit patterns and electrodes on the glass substrates of plasma display panels. The technique can accelerate fabrication time by as much as 30 times, it is claimed. Circuit patterns and electrodes are normally fabricated on the glass substrates by coating the entire sheet with a photosensitive resin mixed with silver paste. This is followed by drying, transferring the pattern using a mask and photolithography, then developing and baking. In the new method, the glass is coated with a sticky photopolymer, which is then exposed to ultraviolet light through a photomask. This hardens the resin except where the circuits and electrodes are to be laid down. A roller covered in silver paste goes across the glass and the remaining pattern of sticky resin grabs hold of the silver paste. Baking then binds the silver to the glass to form the circuits and electrodes. The new procedure eliminates the drying stage, enabling photolithography to proceed more quickly because the silver is laid down afterward. DuPont KK will begin operating a pilot line in June 2005 and plans to market the technology to plasma panel glass manufacturers.