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DOE 활용 추력리플성분 저감을 위한 PMLSM 고정자 형상 최적화
권준환,김재경,전의식 한국반도체디스플레이기술학회 2021 반도체디스플레이기술학회지 Vol.20 No.4
Permanent magnet linear synchronous motor (PMLSM) is suitable for use in cleanroom environments and have advantages such as high speed, high thrust, and high precision. If the stators are arranged in the entire moving path of the mover, there is a problem in that the installation cost increases. To solve this problem, discontinuous armature arrangement PMLSM has been proposed. In this case, the mover receives a greater detent force in the section where the stator is not arranged. When a large detent force occurs, it appears as a ripple component of the thrust during PMLSM operation. If the shape of the stator is changed to reduce the detent force, the characteristics of the back EMF are changed. Therefore, in this paper, the detent force and the harmonic components of back EMF were reduced through multi-purpose shape optimization. To this end, the FEA model was constructed and main effect analysis was performed on the major shape variables affecting each objective function. Then, the optimal shape that minimizes the objective function was derived through the response surface analysis method.
전용백,권준환,백홍렬 대구대학교 과학기술연구소 1998 科學技術硏究 Vol.5 No.1
This study about consolidated undrain test are performed for the different preconsolidation stress, the void ratio and shear strength parameter versus of the clay which make use of the Data Logger and Computer System and the existing theories are compared with existing theories. The summary of experiments as follows 1. The preconsolidation stress and shear strength appeared as r= σ_(e)tan 11.46˚+ σtan 19.44˚ this equation enables to know the shear strength when the preconsolidation strength and the confining stress are know. 2. The shear strength parameter decrease in proportion to void ratio at the degree of over consolidation, and the void ratio decrease in proportion to preconsolidation stress, so the change of preconsolidation ratio is equal to the change of shear strength parameter. The preconsolidation stress has no effect on the internal friction angle but has direct effect on the change of cohesive force, and the relation between preconsolidation stress and cohesive force is c= 0.2288P- 0.0541. 3. The internal friction angles are equal at the same sample by the Mohr-Coulomb's theory, but in this experiment, it was appeared that the cohesive strength decrease in proportion to void ratio through the variation of void ratio and the internal friction angle has nothing to do with void ratio.
실험계획법을 이용한 Reel Tape Packaging 공정조건 분석
김재경,나승준,권준환,전의식 한국반도체디스플레이기술학회 2020 반도체디스플레이기술학회지 Vol.19 No.2
Today’s placement machines can pick and place thousands of components per hour with a very high degree of accuracy. The packaged semiconductor chips are inserted into a carrier at regular intervals, covered with a tape to protect the chips from external impact, and supplied in a roll form. These packaging processes also progress rapidly in a consistent direction, affecting the peelback strength between the cover tape and carrier depending on the main process conditions. In this paper, we analyzed the main process variables that affect peelback strength in the reel tape packaging process for packaging semiconductor chips. The main effects and interactions were analyzed. The peelback strength range required in the packaging process was set as the nominal the best characteristics, and the optimum process condition satisfying this was derived.