Six Sigma program has been considered as a powerful business strategy that employs a well-structured continuous improvement methodology to reduce process variability and to raise quality within the business process effectively using statistical tools and techniques. This paper presents a procedure that applies six sigma program to improve quality in the manufacturing of SMT. The case illustrates how the define-measure-analyze-improve-control (DMAIC) approach has been used. Firstly, we find out the key factor of the quality characteristic and evaluate the repeatability and reproducibility of the measurement system. After confirming the process of the capability, we find out the key factor, which affects the process, and then use “Taguchi Methods ”to get the ultimate process parameter. Taguchi Methods is also called quality engineering. It is a systematic methodology for product design (modify) and process design (improvement) with the most of saving cost and time, in order to satisfy customer requirement. Taguchi’s parameter design is also known as robust design, which has the merits of low cost and high efficiency, and can achieve the activities of product quality design, management and improvement, consequently to reinforce the competitive ability of business.r
