應用六標準差方法於TFT LCD Cell製程之微小亮點良率改善

Abstract

在高階智慧型手機液晶顯示器技術的競爭上，由於市場不斷的推進，使得手機廠商在手機顯示器的尺寸、解析度及技術方面都必須每一年以快速推進方式，以獲得更多商機與市場佔有率，然液晶顯示器之製程良率影響成品之成本及品質頗巨，本研究以某中小型TFT LCD手機面板廠為例，運用六標準差DMAIC的方法，由界定 (Define)、衡量 (Measure)、分析 (Analyze)、改善 (Improve)、控制 (Control) 之改善歩驟，以改善TFT-LCD Cell製程中的微小亮點缺陷，從傾聽客戶聲音並結合公司策略開始，根據經營績效指標，訂出改善之KPI(Key Performance Index) ，確認六標準差專案工作重點, 據以展開持續改善專案，進行各項實驗以及應用統計方法分析，找出重要影響因子並進行優化與控制，最後監控指標的改善成效以及評估整體的效益。透過六標準差手法及DOE實驗可減少製程變異，達到預期的品質目標不良率由17%降至2% ，另外也達到了減少實驗次數的效益，並達到整年度財務改善近五億元之績效。

In the competition of high level smart phone LCD (Liquid Crystal Display) technology, due to the advancement of market, the size, resolution and technology of mobile phone display need to be improved by manufacturers every year to gain more business opportunity and market share. However, the yield of LCD has a great influence on the cost and quality of finished product.

This study takes a small and medium sized TFT LCD mobile panel manufacturer as example, by using the method of Six Sigma DMAIC, through the improvement process of Define, Measure, Analyze, Improve and Control, so as to improve the defect of small tiny bright dot in the processing of TFT-LCD Cell. Meanwhile, by listening to the voice of customers and combining company strategy, according to the business performance index, Key Performance Index is drew up to make sure the emphases of Six Sigma project, by which continuous improvement project, various experiments and statistic method are conducted, so as to find out important impact factor and conduct optimization and control, finally, the improvement result of index is monitored as well as the overall efficiency is evaluated.

Through Six Sigma Method and DOE (Design of Experiments), process variation could be reduced, the quality target could be reached and the reject ratio could be reduced from 17% to 2%. In addition, the number of experiments is also reduced and an annual financial improvement of almost 0.5 billion is reached as well.