| Summary: | 碩士 === 國立交通大學 === 工業工程與管理系所 === 97 === Statistical Process Control (SPC) has been widely employed in many industries, especially in high-tech manufacturing. In SPC, the X-BAR control chart is generally implemented in wafer manufacturing and it is designed to monitor the quality of product data for single source of variation. However, there are multiple variations exist in wafer-manufacturing process and this restricts the use of X-BAR control chart. Wells and Smith[20] proposed a three-step control process for monitoring the wafer production. However, their proposed process cannot detect small shift in the process. In addition, when employing chart the data must be independent. Once autocorrelation exist in data, the control limits will be underestimated and false alarms will be increased. Hence, the main objective of this study is to propose a statistical process controlling procedure for multiple-time intervals and multiple measured points wafer data with autocorrelation. Furthermore, the small shifts and large shifts can simultaneously be detected using the proposed procedure.
A real case is utilized to demonstrated the effectiveness of the proposed procedure.
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