• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.70-70
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• 2011

표면처리는 전기적, 물리적, 화학적 처리방법 등을 통해 보호표면을 생성시킴으로서 재료의 외관미화, 내마모성, 전기절연, 전기전도성 부여 등의 폭넓은 목적을 달성시키고자 하는 일련의 조작을 말한다. 최근 스마트 휴대폰으로 대표되는 이동통신기기 산업의 빠른 성장으로 인하여 이들 기기를 보호하기 위한 표면 처리기술도 함께 발전하고 있다. 그중 대표적인 것이 나노기술을 융합한 보호막 도장기술이다. 나노입자를 분산하거나 나노상(phase)을 융합하여 제품의 표면에 보호막을 도장하는 기술이며, 그 주된 목적은 내 스크래치, 내 부식 등의 물리 화학적 보호기능을 수행하도록 층(layer)을 형성하는 것이다. 본 연구에서는 제조된 실리카 나노입자와 유기물을 사용하여 휴대폰 케이스에 도장막을 형성하였고, Scratch, Wear, hardness Test등의 분석을 통하여 유무기 하이브리드 도장막의 특성을 평가하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.243-243
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• 2003

무기 나노 입자와 유기물간의 균일한 화학적 결합으로 제조된 나노 구조형 재료는 수많은 용도에 부응할 수 있는 기계적, 전기적 및 광학적 특성을 설계, 제조하는데 유용한 방법으로 사용되고 있다. 이중 화학적 습식 졸-겔 공정은 나노 구조형 유/무기 하이브리드 재료 제조에 매우 효과적인 방법으로 알려져 있으며 내부식성 금속 코팅막, 내 스크래치 코팅막 제조에 활용되고 있다. 그러나 무기 나노 졸 입자와 유기물과의 매개로 작용하는 커플링제와의 하이브리드 과정에 대한 정보는 극히 조금 알려져 있다. 본 연구에서는 알루미나 나노 졸과 GPS((3-glycidoxypropyl-triethoxysilane)와의 하이브리드 생성 과정을 이온 전도도 측정으로 관찰한 결과를 보고하고자 한다. 알루미나 나노 졸은 Al(NO$_3$)$_3$.9$H_2O$ 수용액에 NH$_4$OH를 가하여 침전물을 얻고 여과 및 수세하여 졸 입자의 함량이 약 5 wt%가 되게 이온교환수와 해교제인 초산을 소량 가하여 10$0^{\circ}C$에서 약 50시간 열처리하는 방법으로 제조하였다. 알루미나 졸 입자와 GPS와의 결합 과정을 reactor FT-IR로 시간에 파라 연속적으로 분석하여 그 반응 경로를 이온 전기전도와 비교하여 논의 될 것이다. 아래 그림 1은 알루미나 나노 졸에 GPS를 첨가한 후 시간에 따라 얻어진 이온 전기전도도를 나타낸 그림이다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1109-1112
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• 2004

This paper presents a high sensitive force sensing module to measure machining forces for a tip-based nanopatterning instrument. The force sensing module utilizing a leaf spring mechanism and a capacitive displacement sensor has been designed to provide a measuring range from 80$\mu$N to 8N. This force sensing module is mounted on a PZT driven in-feed motion stage with 1 nm resolution. The sample can be moved by a X-Y scanning motion stage with 5 nm resolution. In the patterning experiments, the machining forces were controlled and monitored by the force sensing module. Then, the patterned sample was measured by AFM. Experimental results demonstrated that the developed force sensing module can be used as an effective sensing device in the nanopatterning operation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.355-358
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• 2004

In this study, the deformation characteristics of grain-size controlled rheology materials surfaces were investigated as a part of the research on the surface crack prediction in semi-solid formed automobile components. The microstructure of rheology Al-Si alloys consists of primary and eutectic regions. In eutectic regions the crack initiation begins with initial fracture of the eutectic silicon particles and inside other intermetallic phases. Nano-deformation characteristics in the eutectic and primary region of semi-solid aluminum alloys (356 alloy and 319 alloy) were investigated through the nanoindentation/scratch experiments and the AFM observation.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.4
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• pp.393-400
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• 2012

In recent years, nano-structured thin film systems are often applied in industries such as MEMS/NEMS device, optical coating, semiconductor or like this. Thin films are used for many and varied purpose to provide resistance to abrasion, erosion, corrosion, or high temperature oxidation and also to provide special magnetic or dielectric properties. Quite a number of articles to evaluate the characterization of thin film structure such as film density, film grain size, film elastic properties, and film/substrate interface condition were reported. Among them, the evaluation of film adhesive to substrate has been of great interest. In this study, we fabricated the polymeric thin film system with different adhesive conditions to evaluate the adhesive condition of the thin film. The nano-structured thin film system was fabricated by spin coating method. And then V(z) curve technique was applied to evaluate adhesive condition of the interface by measuring the surface acoustic wave(SAW) velocity by scanning acoustic microscope(SAM). Furthermore, a nano-scratch technique was applied to the systems to obtain correlations between the velocity of the SAW propagating within the system including the interface and the shear adhesive force. The results show a good correlation between the SAW velocities measured by acoustic spectroscope and the critical load measured by the nano-scratch test. Consequently, V(z) curve method showed potentials for characterizing the adhesive conditions at the interface by acoustic microscope.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.363-366
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• 2003

In nanomachining processes, chemical effects are more dominant factor compared with physical deformation. For example, during the nanoscratch on a silicon surface in the atmosphere, micro protuberances are formed due to the mechanochemical reaction between the diamond tip and the surface. On the contrary, in case of chemically stable materials, such as ceramics or glasse, the surface protuberance are not formed. The purpose of this study is to understand effects of the mechanochemical reaction between tip and surfaces on deformation behaviors of hard-brittle materials. Nanometerscale elasoplastic deformation behavior of single crystal silicon (100) was characterized with the surface protuberance phenomena, and compared with that of borosilicate (Pyrex glass 7740).

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.47-52
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• 2018

In this study, the effects of the heat treatment and multi-scale hierarchical structures on the durability of the nano-patterned functional PMMA(Poly(methyl-methacrylate)) film was evaluated. The heat treatments that consisted of high-pressure/high-temperature flat pressing and rapid cooling process were employed to improve mechanical property of the PMMA films. Multi-scale hierarchical structures were fabricated by thermal nanoimprint to protect nano-scale structures from the scratch. Examination on surface structures and functionalities such as wetting angle and transmittance revealed that the preopposed heat treatment and multi-scale hierarchical structures are effective to minimize surface damages.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.3
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• pp.41-46
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• 2017

In this study, rapid cooling method was proposed to improve the anti-scratch performance of anti-reflection film fabricated by nanoimprint lithography. Effects of cooling time on the mechanical properties and optical properties were evaluated. Pencil hardness measurements showed that anti-scratch performance enhanced as the cooling time increased while characterization on the optical property showed that reflectance on scratch increased as the cooling time increased. Therefore, it was concluded that the anti-scratch performance and optical properties are highly influenced by the cooling time. The observed results explained in terms of residual stress and free volume in polymeric materials.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.351-354
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• 2004

This work presents a simple and cost-effective approach for maskless fabrication of positive-tone silicon master for the replica molding of hyperfine elastomeric channel. Positive-tone silicon masters were fabricated by a maskless fabrication technique using the combination of nanoscratch by Nanoindenter ⓡ XP and XOH wet etching. Grooves were machined on a silicon surface coated with native oxide by ductile-regime nanoscratch, and they were etched in a 20 wt％ KOH solution. After the KOH etching process, positive-tone structures resulted because of the etch-mask effect of the amorphous oxide layer generated by nanoscratch. The size and shape of the positive-tone structures were controlled by varying the etching time (5, 15, 18, 20, 25, 30 min) and the normal loads (1, 5 mN) during nanoscratch. Moreover, the effects of the Berkovich tip alignment (0, 45$^{\circ}$) on the deformation behavior and etching characteristic of silicon material were investigated.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.255-255
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• 2012

DLC (Diamond Like Carbon) 박막은 높은 경도, 낮은 마찰계수, 내화학성 등의 우수한 트라이볼로지적 특성을 가지고 있기 때문에 다양한 산업분야에서 적용되고 있다. 하지만 강재에 대한 밀착력과 내열성은 단점으로 부각되어왔다. 이에 본 연구는 그런 단점을 보완하고자 PECVD(Plasmas Enhanced Chemical Vapor Deposition) 방법으로 DLC박막에 여러 가지 첨가원소(F,N,O)를 사용하여 증착시킨 후 그에 따른 기계적 특성을 평가하였다. DLC박막의 구조는 Raman Spectra을 통해, Sp3 (like diamond) peak와 Sp2 (like graphite) peak의 혼재 여부를 분석하였고, FE-SEM을 이용하여 막의 표면 및 단면을 관찰하였다. 스크래치 테스트를 통해 DLC박막의 밀착력을 측정하였으며, 볼 온 디스크 타입의 Tribo-meter을 이용하여 마찰계수 변화를 관찰하였다. 또한 나노인덴터를 이용하여 미소경도를 측정하였다. 그 결과 첨가원소에 따라 기계적 특성이 각각 다르게 나타났으며, DLC막이 가지고 있는 장점인 여러 분야에 적용시킬 수 있는 방안을 마련하고자 하였다.