• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.153-154
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• 2007

본 논문에서는 반도체 패키징 기술의 일종인 TCP와 COF의 패턴 결함을 검출하는 영상 처리 알고리즘을 제안한다. 제안된 방법은 우선, TCP와 COF의 양품 패턴을 기준 영상으로 취득한다. 라인 스캐너에서 취득된 실시간 영상을 그레이로 변환한 후, 평균화 필터를 적용하고 임계값을 이용해서 검사하고자 하는 필름 영상의 이진화를 수행한다. 이진화 된 기준 영상과 검사하고자 하는 필름 영상을 이용해서 차영상을 구한 후에 라벨링을 하여 필름의 불량을 검출하게 된다. 제안된 패턴 매칭 방법이 TCP와 COF의 다양한 불량 항목 중에서 10여 가지의 불량 패턴을 대상으로 제안된 방법의 타당성을 검증하였다.

• Nuclear Engineering and Technology
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• v.35 no.2
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• pp.133-143
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• 2003

Stem-stem nut coefficient of friction(COF) in motor-operated gate/globe valves is one of the important factors which determine the performance of the valve/actuators. The COF is affected greatly by the type and condition of the stem-stem nut lubricants, environmental parameters, surface condition of the stem/stem-nuts, and the number of strokes after the lubrication. In this paper, the measured data of the COFs at stem threads of some safety-related motor-operated gate/globe valves in domestic nuclear power plants are presented. In addition, the performance of the lubricants is evaluated by comparing the COFs among those valves. The results show that the measured COF at torque switch trip are higher than the unwedging COF and conservatively applicable to the unwedging COF. It is also shown that the lubricating performance based on the measured COFs varies with the lubricants.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.09a
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• pp.21-30
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• 2002

According the difference of flex substrate, (reel tape), there are three kind assembly types of LCD driver IC is COG, TCP and COF, respectively. The TCP is the maturest in these types for stability of raw material supply and other specification. And TCP is the major assembly type of LCD driver IC and the huge demand from Taiwan's large TFT LCD panel house since this spring. But due to its package structure and the raw material applied in this package, there is some limitation in fine pitch application of this package type, (TCP). So, COF will be very potential in compact and portable application comparison with TCP in the future. There are three kinds assembly methods in COF, one is ACF by using the anisotropic conductive film to connect the copper lead of tape and gold bump of IC, another is eutectic bonding by using the thermo-pressure to joint the copper lead of tape and gold bump of IC, and last is NCP by using non-conductive paste to adhere the copper lead of tape and gold bump of IC. To have a global realization, this paper will briefly review the status of Taiwan's large TFT panel house, the internal driver IC design house, and the back-end assembly house in the beginning. The different material property of raw material, PI tape is also compared in the paper. The more detail of three kinds of COF assembly method will be described and compared in this paper.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.33-42
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• 2015

오늘날 연성회로기판(FCCL : Flexible Copper Clad Laminate)은 디스플레이, 스마트폰, 자동차, 항공, 의료 기기, 산업용 컨트롤 기기 등 거의 모든 고급 전자 제품들에 사용되고 있다. 특히 디스플레이 분야에서는 뛰어난 연성과 내구성을 바탕으로 경박단소화에 유리할 뿐만 아니라 구동부에 적용이 가능한 장점 등으로 그 적용처가 점점 늘어나고 있는 추세이다. 이 가운데서도 LCD와 OLED의 구동소자(Display Driver IC)를 장착하는 COF(Chip on Film)는 대표적인 연성회로기판(FCCL) 적용 부품으로서, 최근 인기를 끌고 있는 디스플레이의 제로-베젤(Zero-bezel)을 가능케 하는 핵심 부품이다. COF용 연성회로기판(FCCL) 소재로는 우수한 평탄도, 파인피치(Fine-pitch)구현성, 내굴곡성, 광투과성 등을 보유하고 있는 Sputtering Type FCCL이 사용되고 있다. 특히 최근 Display 분야의 화두가 되고 있는 POLED(Plastic-OLED) 패널을 장착한 Flexible Mobile 디스플레이의 경우, 기존의 COG(Chip on Glass) 접합방식이 아닌 COF 접합방식을 채택하고 있으며, 기존의 단면 COF보다 3배의 고해상도 구현이 가능한 양면 COF를 채택하기에 이르렀다. 기존의 COF 제작공정과 달리 Semi Additive 공정으로 제작되는 양면 COF 시장의 태동으로 양면 연성회로기판(FCCL)의 수요 증가가 예상되는 등 최근 디스플레이 기술 발전은 소재 분야에도 큰 변화를 잉태하고 있다. 이러한 최근 디스플레이 업계의 고해상도, 고속 신호 전송, 슬림화, Flexible 추세에 대응 가능한 최적의 특성을 보유하고 있는 Sputtering Type FCCL을 중심으로 디스플레이의 발전에 대응하는 소재의 기술 개발 동향을 살펴보고자 한다.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.455-459
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• 2023

Three different optimization studies were conducted for the synthesis of MIL-100(Fe) and MIL-100(Fe)@COF using design of experiments. In the first study, the optimal concentration of precursors was determined using a mixture design method, and a modified molar ratio of 0.4155:0.2664:0.3182 was found to yield the highest crystallinity. In the second study, a central composite design was used to optimize the main factors of synthesis temperature and time with a synthesis temperature of 161℃ and a synthesis time of 12 hours. In the third study, a screening design method was used to determine the effect of five precursors on the formation of MIL-100(Fe)@COF, and the presence of characteristic peaks at 1552, 1483, and 1354 cm^-1 was found to be important for the existence of the COF structure. MIL-100(Fe)@COF synthesized with a modified molar ratio of 0.4831:0.4169:0.1 was predicted to exhibit optimal conditions.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.05a
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• pp.11.2-11.2
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• 2007

• Transactions on Electrical and Electronic Materials
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• v.8 no.1
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• pp.26-31
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• 2007

The goal of this study is to determine if High Pressure Micro Jet (HPMJ) conditioning can be used as a substitute for, or in conjunction with, conventional diamond pad conditioning. Five conditioning methods were studied during which 50 ILD wafers were polished successively in a 100-mm scaled polisher and removal rate (RR), coefficient of friction (COF), pad flattening ratio (PFR) and scanning electron microscopy (SEM) measurements were obtained. Results indicated that PFR increased rapidly, and COF and removal rate decreased significantly, when conditioning was not employed. With diamond conditioning, both removal rate and COF were stable from wafer to wafer, and low PFR values were observed. SEM images indicated that clean grooves could be achieved by HPMJ pad conditioning, suggesting that HPMJ may have the potential to reduce micro scratches and defects caused by slurry abrasive particle residues inside grooves. Regardless of different pad conditioning methods, a linear correlation was observed between temperature, COF and removal rate, while an inverse relationship was seen between COF and PFR.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.112-118
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• 2021

In this study, an inspection method using a color image is proposed to conduct a real-time inspection of covalent organic framework (COF) films to detect defects, if any. The COF film consists of an upper pattern SR and a lower PI. The proposed system detects the defects of more than 20 ㎛ on the SR surface owing to the characteristics of the pattern, whereas on the PI surface, it detects defects of more than 4 ㎛ by utilizing a micro-optical system. In the existing system, it is difficult for the operator to conduct a full inspection through a high-performance microscope. The proposed inspection algorithm performs the inspection by separating each color component using the color contrast of the pattern on the SR side, and on the PI surface it inspects the bonding state of the mounted chip. As a result, it is possible to confirm the exact location of the defects through the SR and PI surface inspections in the implemented inspection.

• Imaging Science in Dentistry
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• v.49 no.3
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• pp.229-234
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• 2019

Central odontogenic fibroma (COF) is defined as a fibroblastic odontogenic tumor characterized by varying density of the tooth epithelium. It is an extremely rare benign neoplasm that occurs in the maxilla and the mandible; only a few reports of COF are available in the literature. Diagnosis of the lesion based only on the radiological features of COF is difficult due to variation in the findings regarding this condition. This report describes 2 clinical cases of middle-aged women with COF. Clinical examination revealed palatal mucosal depression; additionally, oral examination, as well as panoramic radiographs, intraoral radiographs, and computed tomography scans, revealed severe root resorption. This report highlights the clinical and radiological imaging features of COF, with the goal of enabling straightforward differential diagnosis of the lesion by the clinician and thereby appropriate treatment of the patient.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.775-778
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• 2010

본 논문에서는 초미세 패턴($24{\mu}m$ 이하의 선폭, $30{\mu}m$ 이하의 피치)을 가진 칩-온-필름(Chip-on-Film, COF)에 발생한 결함을 자동으로 검출할 수 있는 시스템을 제안한다. 개발된 시스템은 COF 패턴으로부터 대표적으로 발생하는 결함들, 즉 개방(open), 단락(hard short), mouse bite(near open) 및 near short(soft short)을 자동으로 신속히 검출할 수 있는 기술이 적용되어 있다. 특히 초미세 패턴의 경우, near open 및 near short과 같은 결함 검출이 불가능한 기존 검출시스템의 문제점을 극복한 기술이 제안되어 있다. 본 논문에서 제안하는 결함 검출 원리는 미세 선의 결함유무에 따른 저항 변화를 자동으로 검출하고, 그 미세한 변화를 좀 더 자세하게 판별하기 위해 고주파 공진기(resonator)를 적용하고 있다. 제안된 시스템은 미세 패턴을 가진 COF 제작 과정에서 발생한 결함을 신속히 검출할 수 있기 때문에 COF 불량 검사에 소요되는 많은 경비를 줄일 수 있으리라 기대한다.