The Application Of SPC In High Mix Low Volume SMT Production

With the rapid development of information technology, Surface Mount Technology (SMT), an advanced assembly technology with only several decades, spreads and is applied quickly and widely in kinds of electric products and assemblies. Due to SMT involves many industrial technologies, a lot of factors impact quality during process, such as material quality, manufacturing accuracy, manufacturing speed, information transfer and share, operator skill, environment and so on. And apply advanced quality management strategy, select suitable quality management tool, and control product quality truly and timely are very hot currently.This paper concludes internal and oversea main research results for SPC under high mix low volume production, then comments their advantages and disadvantages, and set up own research method with Bayes modeling theory. Through brief introduction of SMT main processes, analyze root causes of common defects during SMT process and find the base of real application to define quality character for subsequent sampling process. After that, analyze the existing problem while using control chart and process capacity indication to evaluate stability of SMT process with necessary basic SPC theory. To fix the problem, with Bayes theory, remedy control parameter to make limitation more accurate in both situations with history data and without history data; and verify the analysis result with a real sample in printing station. The sample analysis shows the corrective method of this paper can make SPC judgment result match real production status more reliable and more accurate.