Robust Optimization of the Powder Composition for the Core of Thin and High Current Inductors

• Main Authors: Ming-Te Cheng, 鄭明得
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/21292505290711827200

碩士 === 國立高雄第一科技大學 === 機械與自動化工程所 === 97 === The iron core of inductors can be classified into Ni-Zn oxide and Mn-Zn oxide. Current package designs are mostly of open types. However, the coil exposure of open package design causes ununiform distributions of magnetic lines of force and low saturation currents. Closed package designs of inductors have the features of a lower resistance, a higher inductance, and a higher allowable current. Many inductor industries aim to develop closed inductors. But the manufacturing process is different from conventional open inductors. Closed inductors apply integrated molding of coils and powders at one time instead of conventional powder sintering. This thesis addresses the optimum mixture design of metallic and adhesion powders for the iron core of a closed inductor. The study applies Taguchi’s experimental designs to analyze the effects of the mixture proportions on the inductance quality, the heat rating current and the saturation current. Pareto optimization is applied to solve for the multi-objective problem. An Utopian optimum is derived at the end of the searching process. The optimum design is verified from a test production run and compared with the initial design. The deviation of the mean inductance of the optimum design is reduced from 7.2% to 0.9%, which thus increases the yield rate by 11%. The heat rating current increases 13%, and the saturation current increases 55%. The study verfied the design strategy combining Taguchi’s method and Pareto optimization in the multi-objective optimization for the mixture design of the iron core, and provided a high quality closed inductor.