• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.509-510
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• 2006

• 대한기계학회논문집A
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• 제34권12호
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• pp.1805-1810
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• 2010

본 논문에서는 알루미늄 박판의 다단 전해식각을 공정을 이용한 3 차원 마이크로 구조물 제작방법을 제안한다. 본 공정은 기존 전해가공 공정들에 비해 3 차원 구조물의 대량생산이 용이하며, 기존 3 차원 마이크로 금속 구조물의 제작을 위한 다단 도금방법에 비해 간단하고, 경제적일 뿐만 아니라, 성형된 금속 박판을 이용하므로 구조물의 물성이 안정적이다. 본 논문에서는 단일 전해식각 공정을 통한 2 차원 외팔보 열과 다단 전해식각 공정을 통한 3 차원 마이크로 구조물의 제작을 수행하였다. 단일 전해식각 공정에서 평균 수직방향 식각률 $1.50{\pm}0.10 {\mu}m/min$ 와 평균 수평방향 식각률 $0.77{\pm}0.03 {\mu}m/min$을 얻었으며, 이를 이용한 3 차원 마이크로 구조물을 제작한 결과, 수직방향으로 $15.5{\pm}5.8 %$, 수평방향으로 $3.3{\pm}0.9 %$의 제작오차와 $37.4{\pm}9.6 nm$의 표면조도를 보였다.

• 한국결정성장학회지
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• 제9권2호
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• pp.157-161
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• 1999

초크랄스키 실리콘 기판의 뒷면에 형성된 기계적 손상이 미치는 효과에 대하여 고찰하였다. 기계적 손상의 정도는 레이저 여기/극초단파 반사 광전도 감쇠법에 의한 소수반송자 재결합 수명, 습식산화/선택적 식각 방법, 표면 부위 미소 결함 및 X-선 단면 측정 분석으로 평가하였다. 그 결과, 웨이퍼 뒷면에 가해지는 기계적 손상의 세기가 강할수 록 소수반송자 재결합 수명은 짧아지고, 표면 부위 미소 결함 밀도는 비례적으로 증가하였으며, 산화 유기 적충 결함 밀 도와도 상호 일치하였다. 그래서, 표면 부위 미소 결함 기술은 산화 유기 적층 결함을 측정하는데 있어서 통상적인 부식 방법과는 별도로 사용될 수 있다.

• KSTLE International Journal
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• 제3권2호
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• pp.101-109
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• 2002

This paper presents the fabrication and performance inspection of a peristaltic micropump by flow simulation. The valve-less micropump using the diffuser/nozzle is consists of base plate, mid plate, top plate and connection tubes fur inlet and outlet. In detail, the base plate is composed of two diffuser nozzles and three chambers, the mid plate consists of a glass diaphragm for the volumetric change of the pumping chamber. The inlet and outlet tubes are connected at the top plate and the actuator fur pressing the diaphragm is located beneath the top plate. The micropump is fabricated on the silicon wafer by DRIE (Deep Reactive ion Etching) process. The pumping performances are tested by the pneumatic test rig and compared with the simulated results fur various dimensions of diffuser nozzles. The pumping characteristics of the micropump by the volumetric change at the pumping chamber is modeled and simulated by the commercial software of FLOW-3D. The simulated results shows that reverse flow is the inherent phenomena in the diffuser nozzle type micropump, but it can be reduced at the dual pumping chamber model.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권4호
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• pp.410-414
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• 2013

We report the wet etching of titanium nickel (TiNi) films for the production of nano-electro-mechanical (NEM) device. $SiO_2$ and $Si_3N_4$ have been selected as sacrificial layers of TiNi metal and etched with polyethylene glycol and hydrofluoric acid (HF) mixed solution. Volume percentage of HF are varied from 10% to 35% and the etch rate of the $SiO_2$, $Si_3N_4$ and TiNi are reported here. Within the various experiment results, 15% HF mixed polyethylene glycol solution show highest etch ratio between sacrificial layer and TiNi metal. Especially $Si_3N_4$ films shows high etch ratio with TiNi films. Wet etching results are measured with SEM inspection. Therefore, this experiment provides a novel method for TiNi in the nano-electro-mechanical device.

• International Journal of Precision Engineering and Manufacturing
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• 제4권4호
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• pp.51-56
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• 2003

Generally, the build-up printed circuit board manufactured by a sequential process involving etching, plating, drilling, etc, which requires many types of equipments and long lead time. Etching process is suitable for mass production, however, it is not adequate for manufacturing a prototype in the development stage. In this study, we introduce a screen printing technology for prototyping a build-up printed circuit board. As for the material, photo/thermal curable resin and conductive paste are used for the formation of dielectric and conductor. The build-up structure is made by subsequent processes such as formation of a liquid resin thin layer, solidification by a UV/IR light, and via hole filling with a conductive paste. By use of photo curable resin, productivity is greatly enhanced compared with thermal curable resin. Finally, the basic concept and the possibility of build-up printed circuit board prototyping are proposed in comparison with the conventional process.

• 한국정밀공학회지
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• 제29권9호
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• pp.1020-1025
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• 2012

In this study, we fabricated the superhydrophobic and super-water-repellent surface with the micro/nano scale structures using simple conventional silicon wet-etching technique and the black silicon method by deep reactive ion etching. These fabrication methods are simple but very effective. Also we reported the droplet impact experimental results on the micro/nano-scaled surface. There are two representative impact behaviors as "rebound" and "fragmentation". We found the transition Weber number between "rebound" and "fragmentation" statements, experimentally. Additionally, we concerned about the dimensionless spreading diameters for our super-water-repellent surface. The novel characterization method was introduced for analysis including the "fragmentation" region. As a result, our super-water-repellent surface with the micro/nano-scaled structures shows the different impact behaviors compared with a reference smooth surface, by some meaningful experiments.

• 대한소아치과학회지
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• 제30권4호
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• pp.581-592
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• 2003

본연구는 유치와 영구치의 우식상아질을 제거하는 방법에 따른 상아질표면의 변화와 산부식양상, 혼성층의 양상, 그리고 이들이 상아질에 대한 복합레진의 전단결합강도에 미치는 영향을 평가할 목적으로 시행되었다. 92개의 유구치와 92개의 영구 구치를 준비하여 상아질 표면을 노출시키고 인공우식을 유발시켰다. 이중 32개의 유구치와 32개의 영구구치는 $Carisolv^{TM}$과 bur로 삭제후 상아질표면을 SEM관찰하였으며 나머지 치아에서는 레진-상아질간 전단결합강도를 측정하였다. 두가지 접착시스템(Single bond system, self-etching bonding system)과 한 종류의 레진(Z250, 3M)을 사용하였으며 다음과 같은 결과를 얻었다. 1. $Carisolv^{TM}$의 우식치질 제거효과는 영구치보다 유치에서 더 우수하였으며, bur로 제거한 경우보다 더 거친 상아질 표면이 관찰되었다. 2. 산부식처리한 경우 유치와 영구치 모두 우식제거방법과 관계없이 도말층이 제거된 양상을 보였다. 3. Single bond system을 이용한 경우 두터운 $2-4{\mu}m$의 혼성층과 $10-15{\mu}m$의 adhesive layer가 관찰된 반면, self-etching bonding system에서는 비교적 얇은($1-2{\mu}m$) 혼성층만이 형성되었다. 4. 전단결합강도는 유치와 영구치 모두 우식제거방법에 관계없이 Single bonding agent를 적용한 경우에 self-etching bonding agent를 적용한 군보다 유의하게 높게 나타났다(P<0.05). 5. $Carisolv^{TM}$와 self-etching bonding agent 처리군에서 bur와 self-etching system 처리군보다 다소 높은 전단결합강도를 보였으나 유의성은 없었다(P>0.05).

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1277-1281
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• 2007

A Nano-tip as a cold field emitter for inducing a field emission current has manufactured in many ways. In the paper, the electrochemical etching method is used. Thus, in order to optimize the final shape as the field emitter, the reliable fabrication system for electrochemical etching was constructed. In addition, the effective parameters such as applied voltage, submerged length, meniscus height, electrolyte concentration and environmental condition(vibration, humidity, cut-off time) have investigated in detail. By controlling the parameters, reliable tungsten tip for field emitter was fabricated. And the fabricated tungsten tip was evaluated optically. Finally, the very sharp apex of the tungsten tip was observed with scanning electron microscope.

• 한국정밀공학회지
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• 제18권2호
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• pp.111-118
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• 2001

Tungsten probe is the most important part of a probe card, which is widely used for the performance test of wafer chips. Electro chemical etching becomes an exclusive choice for mass production of the tungsten probes. In the mass production, not only the shape of the probe but also the shape distribution of machined probes is important. A new method is proposed for the mass production of the tungsten probes. Tungsten wires are separated by a distance, and dipped into electrolyte. The dipping rate is controlled to shape the probes. Several experimental tests are performed to study the machining characteristics. From the test results, machining parameters including electrical conditions and anode position showed significant influences on the shape, repeatability, precision and quality of sharp tips.