除了追求產能外，品質第一向來也是每間公司的重要目標，大多數企業皆透過持續改善以達到此要求，而最直觀影響產出的當屬良率問題，近來發現異物汙染成為低良率的最大因素，為提升良率，本研究將以降低異物汙染率為目標，藉此減低生產過程中造成的外觀問題及避免機臺將良品誤判為不良品的情況發生。 本研究利用特性要因分析圖、FMEA、實驗設計及戴明循環的 PDCA作為研究方法，再帶入實務應用做改善，而在實務應用中則分為幾個部分，首先將利用特性要因分析圖找出異物汙染可能造成的原因，包含各種機構作動中造成的異物掉落、靜置等下一個製程的過程中有灰塵掉落、機器內部濾網網格過大……等，接著使用 FMEA 找出製程中 RPN 超過 150 的項目，最終結合使用實驗設計及 PDCA進行改善。 透過執行各個改善措施後，最終數據結果顯示各個項目的異常率可從最高 50000ppm 降至最低為 1000ppm，RPN 可從 175 降至 35-70，整體而言改善幅度非常顯著，最後也建議未來可針對異物成份作分析，以此作為進一步的改善方向。 ;Quality First is the goal of a company, and this goal can be achieved by implementing continuous improvement plans. Recently, we found foreign material is one of the common reason to cause low yield. In the pursuit of quality, this research will focus on foreign material reduction to reduce visual inspection fail rate and production machine overkill rate during production process. By using fishbone and failure mode & effects analysis (‘FMEA’), this research demonstrates the methods to resolve possible root causes with design of experiment (‘DOE’) and Plan-Do-Check-Act (‘PDCA’). The possible root cause includes but not limited to foreign material fall down during mechanical movement, dirt during waiting process and oversized mesh in oven. The improvement action in practice is using FMEA to sort out the process with risk priority number (‘RPN’) over 150 and implementing improvement plan of DOE and PDCA. The final results indicates that the fail rate of production process modified with improvement plans could lower to 1000ppm from 50000ppm, and the PRN could lower to 35- 70 from 175. In conclusion, the result of improvement is obviously, and suggest to focus on the composition of material for the next study.
