Optimal Improvement on Cutting Yield Rate in ACF Attach Process of TFT-LCD Module Using Response Surface Method

In TFT-LCD manufacturing process, the ACF is an essential material. To make the driving circuit conductive, the ACF attach process is used in bonding process. Since the total manufacturing cost becomes lower year by year, the ACF material occupies a great deal of manufacturing cost. The boding technology has been changed from the conventional long bar type into short bar type to save the material usage. The parameter setting of the short bar type machine was not initially optimized. The NG rate of short bar type ACF attach process is higher as compared to the long bar type. The rework cost and material cost may increase in the short bar type process. Therefore, the parameter optimization for the associated short bar type ACF attach process becomes an essential problem. The response surface method is adopted to model the problem. The yield rate is selected as objective function for study. In the analysis of response surface method, the plasma clean speed, ACF peeling speed and ACF cutter spring setting are selected three key factors for discussion. Results reveal that the yield rate can be improved up to 99.35%, which is very helpful to improve the manufacturing process.