Abstract
It would cause huge yield loss if wire bonding machine cannot do wire-bonding well in assembly house. This study aims to tackle bond finger nodule problem on IC substrate by deploying DMAIC methodology. At “Define” stage, according to the complaint cases Pareto analysis, the top 1 defect is “Bond finger nodule”, thus, the team assigned by top management to solve this issue. At “Measure” stage, it is to define the project CTQ and standards, such as what is normal bond finger and how to distinguish the bond finger nodule. Measurement system is also required to be analyzed and validated to make sure the measurement system is effective. At “Analyze” stage, the possible factors are listed through “Cause and Effect” analysis and simulation test proceeded on those possible factors and find out the main factors by statistic software, Minitab. At “Improve” stage, DOE (Design of Experiment) conducted to figure out the best process control condition, and perform small volume with the best condition to validate the effectiveness. At “Control” stage, to update the SOP (Standard Operation Procedure) with the optimized levels accordingly and publish to production line to follow. After then, there is no more customer complaint by continual monitoring. Through the Six Sigma DMAIC methodology, the customer complaint is reduced and also yield improved in customer site. Besides, quality cost decreased NTD 1.3 million per month as well. It is encouraging for the team to continually proceed the quality improvement with Six Sigma methodology for defect improvement in the future.