• Journal of Information Display
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• v.8 no.2
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• pp.5-9
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• 2007

We demonstrate novel soft-lithographic techniques for preparing patterned liquid crystal (LC) orientations at an alignment layer. By controlling patterning conditions such as wetting property and operating temperature depending on polymeric materials, multi-directional or modified LC alignment conditions can be simply achieved.

• The Korean Journal of Ceramics
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• v.3 no.1
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• pp.34-36
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• 1997

We have fabricated a patterned diamond field emitter on a silicon substrate. Fine diamond particles were planted on a silicon wafer using conventional scratch method. A silicon oxide film was deposited on the substrate seeded with diamond powder. An array of holes was patterned on the silicon oxide film using VLSI processing technology. Diamond grains were grown using a microwave plasma-assisted chemical vapor deposition. Because diamond could not grow on the silicon oxide barrier, diamond grains filled only the patterned holes in the silicon oxide film, resulting in an array of diamond tips.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.22-26
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• 2011

The application of fast tool servo (FTS) for diamond turning has been investigated extensively. This paper focuses on the fabrication of the sinusoidal microstructure on a roller, which generated by a piezoelectric-assisted FTS. The influence of the machining parameters on the microstructure configuration was investigated. The experiment results point out that the configuration of the machined microstructure depends mainly on the spindle speed, the diameter of roller and the driving frequency of FTS. The calculation method of the microstructure dimension was reported. The turning test results show that the diamond tool can be moved up to 1kHz without any reinjected vibration in the machining and the peak-to-valley amplitude of the machined sinusoidal microstructure is about 12<${\mu}m$

• Journal of ILASS-Korea
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• v.17 no.1
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• pp.20-26
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• 2012

Inkjet printing is one of the direct writing technologies and is able to form a pattern onto substrate by dispensing droplets in desired position. Also, by inkjet technology manufacturing time and production costs can be reduced, and procedures can be more efficient. To form a metal pattern, it must be harmonized with conductive nano ink, printing process, sintering, and surface treatment. In this study, micro patterning of conductive line has been investigated using the piezoelectric printhead driven by a bipolar voltage signal is used to dispense $20-40{\mu}m$ diameter droplets and silver nano ink which consists of 50 nm silver particles. In addition, hydrophobic treatment of surface, overlap printing techniques, and sintering conditions with changing temperature and times to achieve higher conductivity.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3295-3297
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• 1999

This paper presents the fabrication of an electromagnetic micro actuator consisting of a Parylene diaphragm with a spiral copper coil and a permanent magnet. The copper coil is fabricated by electroplating and patterning. The frequency response of the actuator are obtained using a laser vibrometer. When the input voltage is 3 V, the DC deflection is 5 ${\mu}m$, and the resonance frequency is about 35 Hz. Also, the mechanical sensitivity of the actuator diaphragm is 69 ${\mu}m/V$.

• Laser Solutions
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• v.11 no.2
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• pp.20-25
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• 2008

Polyimide is one of the useful materials in industry. The surface treatment of polyimide by a femtosecond laser can help accurate and fine fabrication of microstructure. And it can change the transmittance and reflectance of polyimide, too. We put femtosecond laser pulses on polyimide for rectangular or square type surface treaments and observe the change of transmittance and reflectance. Pulsewidth is 172 fs, laser power changes for fabrication are from 5 mW to 20 mW, and transmittance and reflectance are measured under 20m W, 300m W, and 920 mW. Pulse patterning is stable and almost no unwanted surface damage is shown. As power increases, working depth increases but working line width does not increase significantly. As speed changes, they also have same results. It shows the efficiency of a femtosecond laser is good and thermal damage is small for polyimide.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.168-168
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• 2009

핸드폰, 노트북과 같이 최신경량 전자재료로 만들어지는 전자제품의 수요가 급증함에 따라 반도체 배선의 폭이 점점 작아지고, 이로 인해 프린팅공정을 이용한 미세 배선기술이 활발히 개발되고 있다. 이에 본 연구는 미세배선에 높은 전기전도도를 부여하기 위하여 전기도금을 실시하였으며, 균일한 도금층을 얻기 위하여 첨가제에 따른 분극거동을 분석하고 이를 바탕으로 양극 및 음극 형상에 따른 구리의 성장 거동을 시뮬레이션을 통하여 분석하였다. 균일한 증착을 위해서는 첨가제의 역할도 중요하지만 양극과 음극의 형상에 따라서도 구리성장 거동에 영향을 미치는 것을 알 수 있었다.

• Journal of the Korean Society of Visualization
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• v.21 no.1
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• pp.26-30
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• 2023

Interaction of a droplet and substrate is important to determine the coating and final deposition pattern in inkjet printing system. In particular, an accurate deposition of the droplet should be guaranteed for high-resolution patterning. In this study, we performed high-speed shadowgraph experiments on droplet train impact in inkjet system. From the high-speed images, we observed an unexpected bouncing phenomenon. We have found two factors affecting bouncing regime; the Weber number and the curvature of deposited droplet. Experimental results indicate that there is a critical curvature diameter of deposited droplet, which splits into bouncing and merging regime. From this result, we obtained a power-law behavior between the Weber number and the curvature. The understanding of bouncing phenomena helps to improve the accuracy and productivity of inkjet printing.

• Journal of the Korean institute of surface engineering
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• v.46 no.3
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• pp.99-104
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• 2013

The simple and cost-effective microfabrication method of photosensitive glass (PSG) using metal patterning and blank exposure was proposed. Conventional photolithography for micromachining of PSG needs a costly quartz mask which has high transmittance as an optical property. However, in this study the process was improved through the combination of micro-patterned Ti thin film and blank UV exposure without quartz mask. The effect of UV exposure time as well as the DHF etching condition was investigated. UV exposure test was performed within the range from 3 min to 9 min. The color and etch result of PSG exposed for 5 min were the most clear and effective to etch more precisely, respectively. The etching results of PSG in diluted hydrofluoric acid (DHF) with a concentration of 5, 10, 15 vol% were compared. The effect on the side etch was insignificant while the etch rate was proportional as the concentration increased. 10 vol% DHF results not only high etch rate of 75 ${\mu}m/min$ also lower side etch value after PSG etching. This method facilitates the microfabrication of PSG with various patterns and high aspect ratio for applying to advanced applications.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.428-435
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• 2002

Pyroelectric $Pb(Zr_{0.3}Ti_{0.7})O_3$ (PZT30/70) thin film IR detectors has been fabricated and characterised. The PZT30/70 thin film was deposited onto $Pt/Ti/Si_3N_4/SiO_2/Si$ substrate by the sol-gel process. Four different substrate conditions were studied for their effects on the pyroelectric responses of the IR detectors. The substrate conditions were the combinations of the Si etching and the Pt/Ti patterning. In the Si etched substrate, the $Si_3N_4/SiO_2$ composite layer was used as silicon etch-stop, and was used as the membrane to support the PZT pyroelectric film element as well. The measured pyroelectric current and voltage responses of detectors fabricated on the micro-machined thin $Si_3N_4/SiO_2$ membrane were two orders higher than those of the detectors on the bulk-silicon. For detectors on the membrane substrate, the Pt/Ti patterned detectors showed a 2-times higher pyroelectric response than that of not-patterned detectors. On the other hand, the pyroelectric response of the detectors on the not-etched Si substrate was almost the same, regardless of the Pt/Ti patterning. It was also found that the rise time strongly depended on the substrate thickness: the thicker the substrate was, the longer the rise-time.