Finding the key factors for multiple-response manufacturing process

• Main Authors: Chi-Chia Cheng, 程紀嘉
• Other Authors: Jeh-Nan Pan
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/60259468305392695634

碩士 === 國立成功大學 === 統計學系碩博士班 === 94 === Multiple-input(factors) and multiple-output(response) problem has been frequently encountered and discussed in many quality improvement projects and case studies. For example, there are four correlated quality characteristics in the solder paste stencil process, i.e. the volume, area and height of solder paste deposited, which can be measured by an inline fully automatic laser-based 3-D solder paste inspection system. In addition, transfer ratio is another response variable used in the key factor analysis of solder paste stencil printing for quad flat package(QFP) and ball grid array(BGA) package. Jianbiao Pan(2004) conducted an experiment to determine which are the critical variables(factors) that control the amount of solder paste deposited and transfer ratio. Six factors selected in his study are stencil thickness, aperture size, aperture shape, board finish, solder paste type, and print speed. This paper proposes a multivariate technique based on the Mahalanobis-Taguchi- Gram Schmit system(MTGS) as well as the desirability function to explore the key factors for the QFP / BGA solder paste stencil printing process. First, an integrated Mahalonobis-Taguchi system(MTS) as well as the MTGS technique are utilized to diagnose the abnormities of the above-mentioned QFP date and then the signal-to-noise(S / N) ratios are calculated for finding the key factors. Furthermore, four correlated response values are converted to their desirability functions in order to find an overall desirability function for the multi-response solder paste stencil printing process. Finally, both the analysis results of MTS / MTGS and Taguchi methods are compared. The results show that our proposed method is more accurate than Taguchi method in searching out the key factors.