An Application Study Of Six-sigma Management To Improve Pcba Yield Of Smt

Company Y is the mobile-phone manufacturing company. The low yield of PCBA of the SMT increases the manufacturing cost and reduces the efficiency of the assembly phone line. Thus Company Y sets up a project using six-sigma to improve production yield. As a result, the company achieves significant result by increasing quality and decreasing rework on poor quality products.The first chapter introduces the manufacturing background of SMT , the flow of PCBA in the mobile-phone manufacturing , the current state of the PCBA yield in Y company and formulates the idea of using the six-sigma technique to solve the problem.The second chapter is the literature review on the development of six-sigma , the introduction of the DMAIC flow and the comparison between six-sigma management and other improvements methodologies.The third chapter focuses on the project-improving PCBA yield of SMT, by means of DMAIC flow of the six-sigma management. At the beginning, team members and the scope of project improvements are defined in the Define step, which has made the foundation of the following analysis. In the Measure step, the measurement system analysis and process capability analysis are conducted. By using the Pareto chart and the C&E diagram, the thesis identifies five factors affecting PCBA yield. In the Analyze step, The thesis conducts a separate analysis of the five factors through hypothesis testing. As a good method for improvement, DOE is used to improve the five factors in the Improve step. In the end, maintenance and control of the improved results are carried out through the standardization files, SOPs and control chart.The direct and indirect results and the significance of this project are analyzed in the forth chapter.