Improvement on Yield of Anisotropic Conductive Film Attach Process in TFT-LCD Module Using Taguchi Method

Abstract

Anisotropic Conductive Film (ACF) is one of the important materials in LCM (Liquid Crystal Module) process, it is used in bonding process to make the driving circuit conductive. Because the price of TFT-LCD is much lower than before in recent years, the ACF cost has higher ratio in manufacture cost. The conventional long bar ACF attach unit is changed to short bar ACF attach unit in new bonding equipment. However, the new type machine was not optimized in process and mechanical design. Therefore, the failure rate of ACF attach process is much higher than the one of conventional method. This wastes the material and rework cost is also invisible. How to make the manufacturing cost down effectively and promote the product quality will be the important concern to keep the product competition. Therefore, the Taguchi method is used to analyze the problem. The ACF attach yield rate is selected to be objective function for optimization. By the optimization of quality characteristic using Taguchi method, the plasma clean speed, ACF peeling speed and ACF cutter spring setting are studied to optimize the design parameters.