The Prediction Models of Defect Inspection Cycle Time in TFT-LCD Panel Industry

[[abstract]]在競爭激烈的TFT-LCD(Thin-film transistor liquid-crystal display)產業中，顧客需求訂單大都要求較短的生產週期時間，因此，現場管理者必須藉由準確的生產週期時間預測工具協助改善。TFT-LCD生產製程中，後段模組的瓶頸站瑕疵檢驗製程作業時間對顧客交期影響就顯得特別重要，其為較接近終端客戶需求產品的工作站，對顧客需求產品短期交期確認扮演最重要角色，一般也是TFT-LCD後段模組製造單位回覆生管及業務單位可完成入庫的主要窗口，因此對TFT-LCD後段模組廠而言，瑕疵檢驗時間的預測準確度及速度，將最直接影響到顧客訂單交期回應時間及達交率良莠。 本研究利用古典時間序列及迴歸分析模型，建構適合於TFT-LCD後段模組製程中瑕疵檢驗時間預測模式，我們並針對各種模型進行預測誤差衡量，以了解較適合瑕疵檢驗站生產週期時間的預測工具，而透過案例分析，我們得知在TFT-LCD面板瑕疵檢驗時間預測上複迴歸分析方法較古典時間序列方法適合且可行的，由分析過程我們亦得知主要影響瑕疵檢驗時間的因素有那些，可供日後管理者作為瓶頸製程改善依據，進而提昇生產效能。[[abstract]]In the TFT-LCD (Thin-film transistor liquid-crystal display) industry prediction of production cycle time is critical for customer orders. To promptly respond customer request about delivery date and time, manufacturers have to approximate production cycle time as precisely as possible. However, the prediction of production cycle time is especially difficult on the defect inspection station because this process is purely manual operation. Besides, the defect inspection station is also the major window of TFT-LCD manufacturing department to reply the stocking information to the production control department and sales department. Hence, it’s important for the TFT-LCD module manufacturers to have good prediction tools for defect inspection time because it will affect the delivery reply time of customer order and the percentage rate of on time delivery. This research applies classical time series approach and multiple regression analysis to establish the prediction models for defect inspection cycle time in TFT-LCD module process. Then an accuracy comparison between the above two prediction methods is discussed through case study. We found out that the model of multiple regression analysis has better prediction power than the model of classical time series. Our analysis also showed the major factors effecting the defect inspection. Manufacturers in TFT-LCD industry could refer our finding to build their own prediction module of defect inspection cycle time for better customer delivery response