• 한국기계가공학회지
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• 제16권5호
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• pp.105-112
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• 2017

In this study, plastics were deformed after molding due to the characteristics of the material. The Taguchi experimental design method was utilized to find the molding conditions that minimized deformation of the plastic bezel to be assembled in an automotive steering wheel. The injection molding conditions applied to the experimental design method are the melt temperature, cavity plate coolant temperature, core plate coolant temperature, and cooling time. Each condition was divided into five levels, and a total of 25 experiments were planned. However, instead of performing 25 actual molding experiments, the injection molding analysis was performed using the Moldflow program, and the deformation values for each molding analysis were obtained. The optimal molding conditions were obtained from these deformation values. The actual injection molding experiment using optimal molding conditions was compared with the deformation amount of the current molded product. The deformation was measured using a precise 3D scanner. The deformation amount of the molded product under optimal molding conditions was 16.1% lower than the deformation amount of the current molded product.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.678-682
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• 2007

It is conducted that study on corner crack protection for various thermal environment in a flat panel display. Most of the consumer electronics consist of a plastic and a metal structure. And different properties of materials could cause failure of structural reliability due to the various operating temperatures. Especially for front bezel with thin and slender structure, the effect of temperature is significant, and the design for crack protection is crucial for thermal reliability of displays. In this study, it is prescribed the behavior of the front bezel in flat panel display for various operation temperatures and proposed design parameters to ensure the structural reliability of displays.

• Current Optics and Photonics
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• 제1권1호
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• pp.45-50
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• 2017

Optical instruments based on polymer-dispersed liquid crystal (PDLC) have been used to inspect transparent electrodes. Generally the operating voltage of an inspection instrument using PDLC is very high, over 300 V, reducing its lifetime and reliability. The operating-voltage issue becomes more serious in the inspection of touch-screen panel (TSP) electrodes, due to the bezel structure protruding over the electrodes. We have theoretically calculated the parameters affecting the operating voltage as a function of the distance between the TSP and the PDLC, the thickness, and the dielectric constant of the sublayers when the inspection module was away from the TSP electrodes. We have experimentally verified the results, and have proposed a way to reduce the operating voltage by substituting a plastic substrate film with a hard coating layer of smaller thickness and higher dielectric constant.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 추계학술대회 논문집
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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.