Product Design of a Precision Recycle-Process Tool for Displays' Color Filters of TFT-LCDs
An effective process was developed using electroremoval as a precision removal-process for indium tin oxide (ITO) thin-film nanostructures from the displays’ color filter surface of thin film transistor liquid crystal displays (TFT-LCDs). The low yield of ITO thin-film deposition is an important factor in semiconductor production. By establishing a recycling process using the ultra-precise removal of thin-film nanostructures, the semiconductor optoelectronic industry can effectively recycle defective products, minimizing both production costs and pollution. For the removal-process, high rotational speed of the electrode (negative-pole) elevates the discharge mobility and results in improved removal. High flow velocity of the electrolyte provides larger discharge mobility and greater removal ability. An adequate gap-width between the negative-electrode and the ITO surface, or a higher working temperature, results in a higher removal rate for ITO thin-films. Also, adequate feed rate of the color filter combined with enough electrical power produces a fast removal rate. Pulsed direct current can improve the effect of dregs discharge and is advantageous to associate with the fast feed rate of the workpiece (displays’ color filter), but it raises the current rating. Electrochemical removal requires only a short period of time to remove the ITO thin-film easily and cleanly.
Z.Y. Shen, M.N. James, W.D. Li, and Y.X. Zhao
P. S. Pa "Product Design of a Precision Recycle-Process Tool for Displays' Color Filters of TFT-LCDs", Advanced Materials Research, Vols. 44-46, pp. 449-454, 2008