應用實驗設計法改善LED晶粒波長量測設備之退貨率-以A公司為例

Abstract

LED Wafer磊晶製程完後經過研磨、拋光、切割、劈裂、擴張成LED晶粒之後，需要經過半自動針測機與測試機量測才能得知光電特性，而電的特性可以分為電流與電壓，光的特性又可以分為波長與亮度，然後依測試結果的特性進行分選晶粒等級。因此需要量測波長重複性高、量測效果穩定的測試機，並可有效確保LED晶粒測試出貨品質。而客戶端購買測試機時，評估的一項指標為測試機的重複性。其重複性越高可以提高校正後量測波長的精密度，因此本論文之研究是以A公司之LED晶粒波長量測設備為例，在產品開發階段時，調整量測波長之最佳化光學參數尚未完備之下，造成一些設備退貨與未驗收，透過實驗設計方法找到量測波長重複性的顯著因子並找到最佳量測波長參數之最佳配方並驗證其結果，並有效解決A公司測試機量測波長重複性不佳同時也改善退貨率之問題，避免不必要的成本與時間。

After LED epitaxy wafer processing, the wafers have to pass through grinding, polishing, cutting, splitting and expansion to become LED dies, and further go through measurement by a semi-automatic prober and tester before we can understand their photoelectric properties. The electrical properties can be classified as current and voltage, and the light properties as wavelength and brightness. After die sorting and grading based on the properties of test results, the dies are aggregated into a map chart for picking. Therefore, a tester with high wavelength repeatability and stable measuring effect are needed to ensure effective detection of shipment quality of LED dies. While purchasing the tester, one evaluation indicator that can be done by the customer side is repeatability. The higher the repeatability, the greater will be the precision of wavelength measurement after rectification. Hence, we took a real case of a company and this case is about the wavelength measurement device of LED die. In product developing stage, engineers can't have the well wavelength measurement parameters so that the wavelength measurement device may not be passed a verification and will be returned. We intend to use the experimental design methodology to explore the optimum formulation of wavelength measurement parameters in order to verify their results. This will improve the tester's poor repeatability issue and the return-rate for decreasing the cost and time of the company.