6시그마와 QFD를 활용한 반도체용 wire공법 최적화 연구

김창희,김광수,Kim, Chang-Hee,Kim, Kwang-Soo 한국벤처창업학회 2012 벤처창업연구 Vol.7 No.3

반도체를 제작하는데 있어 Wire bonding 공정은 가장 정밀한 관리와 핵심품질특성(CTQ)을 필요로 한다. 포장과정에 있어서 가장 필수적인 단계로 간주된다. 이 과정에서는 순금 와이어가 칩과 PCB를 연결하기 위해서 사용된다. 금의 가격은 오랜 기간 동안 꾸준히 증가하여왔고, 근래에도 더 증가할 것으로 예상된다. 이러한 상황에서, 많은 반도체 제조 회사들은 새로운 종류의 와이어를 개발했다. 합금와이어가 그 중 하나이고 그것에 많은 연구가 이루어지고 있다. 본 연구는 Wire bonding 공정에서의 parameter를 6sigma와 품질기능전개(QFD)를 사용해 최적화시키고자 한다. 6sigma 과정은 그 문제를 해결하는데 뿐만이 아니라 생산성을 향상시키는데 좋은 기법이다. 중요한 요인을 찾기 위해서 고객의 소리에 초점을 두었다. 고객의 소리의 주요 요인들은 CTQ라고 불린다. 본 연구는 CTQ의 목표수준을 설정 한 후 중요인자를 선정하기 위하여 QFD 활동을 하였으며, 최적 조건 설정하기 위해 실험계획법을 이용하였다. 따라서 본 논문에서는 품질기능전개에서 신제품 개발 시 공정 조건을 최적화 하는 과정을 제시 하여 양산에서 발생될 수 있는 품질 위험요소를 사전에 제거 시킬 수 있게 되었다. Wire bonding process in making semiconductor needs the most precise control and Critical To Quality(CTQ). Thus, it is regarded to be the most essential step in packaging process. In this process, pure gold wire is used to connect the chip and PCB(substrate or lead frame). However, the price of gold has been skyrocketing continuously for a long period of time and is expected to further increase in the near future. This phenomenon situates us in an unfavorable condition amidst the competitive environment. To avoid this situation, many semiconductor material making companies developed new types of wires: Au.Ag wire is one material followed by many others. This study is aimed to optimize the parameter in wire bonding with the use of 6sigma and QFD(Quality Function Deployment). 6sigma process is a good means to not only solve the problem, but to increase productivity. In order to find the key factor, we focused on VOB(Voice of Business) and VOC(Voice of Customer). The main factors from VOB, VOC are called CTQ. However, there were times when these main factors were far from offering us the correct answer, thus making the situation more difficult to handle. This study shows that QFD aids in deciding which of the accurate factors to undertake. Normally QFD is used in designing and developing products. 6sigma process is held more effective when it used with QFD.

자율주행 경로 추종 성능 개선을 위한 차량 조향 시스템 특성 분석

김창희,이동필,이경수,Kim, Changhee,Lee, Dongpil,Yi, Kyongsu 한국자동차안전학회 2020 자동차안전학회지 Vol.12 No.2

This paper presents steering system requirements to ensure the stabilized lateral control of autonomous driving vehicles. The two main objectives of a lateral controller in autonomous vehicles are maintenance of vehicle stability and tracking of the desired path. Even if the desired steering angle is immediately determined by the upper level controller, the overall controller performance is greatly influenced by the specification of steering system actuators. Since one of the major inescapable traits that affects controller performance is the time delay of the steering actuator, our work is mainly focused on finding adequate parameters of high level control algorithm to compensate these response characteristics and guarantee vehicle stability. Actual vehicle steering angle response was obtained with Electric Power Steering (EPS) actuator test subject to various longitudinal velocity. Steering input and output response analysis was performed via MATLAB system identification toolbox. The use of system identification is advantageous since the transfer function of the system is conveniently obtained compared with methods that require actual mathematical modeling of the system. Simulation results of full vehicle model suggest that the obtained tuning parameter yields reduced oscillation and lateral error compared with other cases, thus enhancing path tracking performance.

자동차 시트벨트의 진동특성 개선을 위한 구조에 관한 연구

김창희,오채은,김태우,송철우,이석순,Kim, Chang-Hee,Oh, Chea-Eun,Kim, Tea-Woo,Song, Chul-Woo,Lee, Seok-Soon 한국기계가공학회 2020 한국기계가공학회지 Vol.19 No.2

To prevent vibration of a vehicle's interior parts due to external impacts, the vehicle should be designed to reduce vibration and increase rigidity. In this paper, we conducted a vehicle test in which the vibration characteristics of a seatbelt resulting from the impact of a person closing a car door were measured and analyzed. A correlation analysis was performed using the finite analysis method. Based on this, a sensitivity analysis was performed, and an improved model was designed. We compared the natural frequencies and mode shapes of the improved and the initial models, which confirmed that the natural frequency of the improved model was more than 10 Hz higher than that of the initial model. Moreover, the response frequency of the improved model was three times higher than the input frequency applied in the vehicle test.

회로팩의 온도가속 수명시험에 관한 고찰

김창희,양충렬,고재상,Kim, Chang-Hui,Yang, Chung-Ryeol,Go, Jae-Sang 한국전자통신연구원 1992 전자통신동향분석 Vol.7 No.3

통신시스팀을 구성하는 PBA수준에 대해 운용중의 고장률 추정 및 고장형태 파악을 목적으로 실시하는 가속수명시험에 대해 서술하였다. 이를 위해 통신 시스팀에서 나타나는 고장 유형 및 각 기간에서의 고장률데이터 확보방법, 가속수명시험의 종류 및 원리, 시스팀을 구성하는 PBA 수준에 대한 가속수명시험조건에 대해 서술하였다.

치과위생사의 한국형 전문치과위생사제도 도입에 대한 견해

김창희,이선미,김형미,Kim, Chang-Hee,Lee, Sun-Mi,Kim, Hyeong-Mi 한국치위생학회 2020 한국치위생학회지 Vol.20 No.2

Objectives: The purpose of this study was to investigate the opinions of Korean dental hygienists on the Korean advanced dental hygienist system in Korea. Methods: The survey was conducted on 328 dental hygienists working at dental clinics and hospitals in Seoul, Gyeonggi-do, Incheon, and Chungcheong-do. Collected data were analyzed with the frequency analysis, independent-samples t-test, and one-way analysis of variance after their reliability and validity were verified through the reliability, exploratory factor, and confirmatory factor analyses. Results: Respondents preferred sectoral advanced dental hygienists to integrated advanced dental hygienists, but 47.0% of respondents did not respond to this questionnaire item. To become an advanced dental hygienist, 'more than 5 years but less than 8 years' of clinical experience was appropriate according to 45.7% of the respondents and 'more than 30 h but less than 40 h' of training period was appropriate according to 25.9% of the respondents. Respondents thought that the duration of the training period for advanced dental hygienists would be directly proportional to expectations from the effect of advanced dental hygienists (p=0.023). Further, respondents who were usually interested in advanced dental hygienists showed higher expectations from the role (p<0.001) and effect (p<0.001) of advanced dental hygienists than those who were not interested. Conclusions: This study suggests various implications of the introduction of the advanced dental hygienist system in Korea.

즉시중합 Resin이 구강조직에 미치는 영향에 관한 실험적 연구

김창희,Kim, Chang-Whe 대한치과의사협회 1980 대한치과의사협회지 Vol. No.

The auther embedded the clinically differently used direct resins to the oral submucosa of the rabbits, and compared the tissue reactions to the direct resins with that to the indirect resins. The results were as follows: 1. Direct resins showed more lympocytes infiltration than indirect resins at the early stage of the embedding, but the same degree of the appearance of lympocytes infiltration as indirect resin at the late stage of the embedding. And the formation of fibrosis around the embedding showed the irregular finidng. 2. Fibrosis of direct resin showed the tendency to be finer than indirect resin at the early stage of the embedding, but direct resin formed the similar fibers capsule to that of indirect resin at the late stage of the embedding.

주류문화 1 - 맛있는 '와인논쟁'

김창희,Kim, Chang-Hui 한국주류산업협회 2010 주류산업 Vol.30 No.2

3-Channel Vaginal Ovoids의 선량분포 특성

김창희,윤상모,김성규,신세원,Kim Chang Hee,Yun Sang Mo,Kim Sung Kyu,Shin Sei One 한국의학물리학회 2004 의학물리 Vol.15 No.3

자궁경부암의 치료에서 자궁적출술 후 시행되는 방사선치료는 국소 재발의 가능성을 줄여 주거나 무병생존율을 향상시켜준다. 수술 후 국소재발이 질강에서 발생하거나, 질의 악성종양을 치료하기 위하여 외부조사와 병합한 강내조사나 강내조사 단독치료가 이용된다. 질강을 통한 강내조사에서는 육안적 또는 영상진단에서 확인되는 종양에는 고선량의 방사선치료가 필요하지만 정상조직에는 최대한 피폭을 적게 해야 된다. 사용하는 치료기에 따라서 다양한 크기의 ovoid applicator가 준비되지 않은 경우에 질강의 해부학적인 특성이 준비된 ovoid applicator와 비교하여 너무 넓은 경우에는 질점막에 원하는 선량분포를 얻을 수 없는 경우가 발생하여 치료의 효과를 떨어뜨리고 치료와 연관된 부작용이 더 많이 발생할 수 있다. 본 연구는 자궁적출술 후 시행되는 질강을 통한 근접치료에서 기존의 상품화된 2-채널 ovoid applicator 에 추가로 한 개의 선원을 더 설치할 수 있도록 3-채널 ovoid applicator를 제작하고 다양한 조건에서 모의치료를 시행하여 선량분포를 서로 비교하였다. Ovoid applicator의 두 선원 사이의 거리가 2 cm와 2.5 cm인 경우에는 기존의 2-채널 ovoid applicator와 새로 제작한 ovoid applicator 사이에 선량분포에서 차이가 없었으나, 양쪽 ovoid applicator 사이의 거리가 3, 3.5, 4 cm으로 증가될수록 기존의 2-채널 ovoid applicator를 사용하는 경우에는 ovoid applicator사이 중간지점에 저선량 부위가 발생하였지만, 새로 보완하여 제작한 3-채널 ovoid applicator를 사용하는 경우에는 저 선량 지점이 발생하지 않았다. 이상의 결과에서 질강이 넓어서 기존의 2-채널 ovoid applicator를 이용할 수 없는 경우에 양쪽 ovoid applicator 사이에 추가로 방사선원을 더 설치할 수 있는 3-채널 ovoid appilcator를 사용하면 질강내 국소재발의 감소와 생존율의 증가에 기여할 것으로 생각되었으며, 향후 더 많은 환자들을 대상으로 장기간에 걸친 임상적인 연구가 필요할 것으로 생각되었다. This study was aimed to develop a new ovoid applicator for vaginal high-dose rate intracavitary radiation therapy, evaluate uniformity of dose distribution, and assess clinical applicability. The authors evaluated dose uniformity of vaginal mucosa according to 5-different ovoid-separation using 2-channel and modified 3-channel ovoid applicator. There were no significant differences in the dose distribution along the vaginal mucosa with 2 and 2.5 cm separations, but there were between the 2-channel and 3-channel ovoid applicator with a separation of 3 cm or more. Although a low dose area was shown between two ovoid applicators with the 2-channel ovoid applicator, the dose distribution along the vaginal mucosa with the 3-channel ovoid applicator was very uniform.

환경조형학과의 당면과제

김창희,Kim, Chang-Hui 한국대학교육협의회 1987 大學敎育 Vol.26 No.-

새로운 한의학 양생 범주에 관한 연구

김창희,임병묵,박해모,정명수,황귀서,신용철,고성규,장보형,이해웅,이영준,신헌태,박선주,현민경,이상재,Kim, Changhee,Lim, Byungmook,Park, Haemo,Jung, Myungsu,Hwang, Guiseo,Shin, Yongchul,Go, Sunggyu,Jang, Bohyung,Lee, Haewoong,Lee, Youngjun,Shin, 대한예방한의학회 2015 대한예방한의학회지 Vol.19 No.1

Objective : This study aimed to develop a new category system of Yanseng(養生) for traditional Korean Medicine in order to prepare the ground for organizing the resources of Yangseng systematically. Method : We reviewed the existing medical books containing Yangseng contents. Based on the experts' consensus, we drew the new category system of Yangseng in consideration of a national trait of Korea and use of Yanseng in modern society. Results : First, We devided Yangseng category into two parts: methods and applications. Methods are divided into 5 parts: mind, diet, herb, Doinangyo(導引按蹻), life. A broad use of herbs in daily life is a national trait of Korea. Doinangyo contains relaxation methods like breathing, massages and exercises like Qigong and is also very popular way to maintain health in modern western society. Applications are divided into 6 parts: type of constitution, life cycle, seasons, type of symptoms and signs, type of Mibyung(未病) and diseases. We drew this 6 parts in consideration of use in the field of health care. Conclusion : The new category system of yangseng is based on existing theories and reflects Korean national trait and use of Yanseng in modern society. We hope this new category system play a role of foundation for organizing the resources of Yangseng systematically.