Flexible plastic substrates are so light and thin that they can be cost effective since they allowed modules to be minimized and light weighted. They are also very effective in fabrication curved surface as well. Plastic substrates were prepared to fabrication flexible display panels using polyimide. Then a processing route including cleaning, Hexamethyldisilazane (HMDS), coating, vacuum drying and baking, was applied before the flexible substrate coating. Real product of flexible substrates was fabricated by applying a new annealing technology. A processing technology and necessary process were introduced for fabrication flexible substrate in this study.