• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.1-6
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• 2022

This computational investigation of micro-sized particle dispersion concerns the fume particle contamination over target surface in high-precision laser line machining process of semiconductor and display device materials. Employing the random sampling based on probabilistic fume particle generation distributions, the effects of sphericity for nonspherical fume particles are analyzed for the fume particle dispersion and contamination near the laser machining line. The drag coefficient correlation for nonspherical particles in a low Reynolds number regime is selected and utilized for particle trajectory simulations after drag model validation. When compared to the corresponding results by the assumption of spherical fume particles, the sphericity of nonspherical fume particles show much less dispersion and contamination characteristics and it also significantly affects the particle removal rate in a suction air flow patterns.

• Journal of Information Display
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• v.7 no.2
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• pp.12-15
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• 2006

We propose a patterning method of liquid crystal (LC) alignment layer for producing multi-domain LC structures. By controlling thermal conditions during micro-contact printing procedures and facilitating wetting properties of patterning materials, patterned LC orientation can be easily obtained on a bare ITO surface or other polymer films. The newly proposed patterning method is expected to be a very useful tool for fabricating multi-domain LC structures to enhance or design electro-optic properties of LC-based devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.514-517
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• 2004

We have studied motion of micro-particle immersed in liquid crystal (LC) controlled by in-plane field, which is an important technology in the electro-phoretic display (EPD). In the EPD on and off states are decided by movement of these charged particles and response time is influenced by moving velocity of charged particles. In addition, the velocity can be controlled by intensity of applied voltage such that the higher the applied voltage, the faster velocity of particles become. In this study, we investigated particles's motion as functions of applied voltage, temperature of LC, rubbing direction,

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.267-269
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• 1994

Various types of plasma display panels(PDPs) have been developed to realize the flat panel display device. But, many of its characteristics must be improved before it can be commercialized. In order to investigate tile characteristics of micro discharge in a PDP ceil, we have constructed a micro-gap discharge system whose electrode gap can be adjustable between $100-1000{\mu}m$ within $0.1{\mu}m$ accuracy. We measured the minimum sustain voltage, current, delay time of discharge while changing parameters(electrode gap distance, electrode surface area, pressure) which influence discharge characteristics.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.167-171
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• 2021

The core-shell InGaN/GaN Multi Quantum Well-Nanowires (MQW-NWs) that were selectively grown on oxide templates with perfectly circular hole patterns were highly crystalline and were shaped as high-aspect-ratio pyramids with semi-polar facets, indicating hexagonal symmetry. The formation of the InGaN active layer was characterized at its various locations for two types of the substrates, one containing defect-free MQW-NWs with GQDs and the other containing MQW-NWs with defects by using HRTEM. The TEM of the defect-free NW showed a typical diode behavior, much larger than that of the NW with defects, resulting in stronger EL from the former device, which holds promise for the realization of high-performance nonpolar core-shell InGaN/GaN MQW-NW substrates. These results suggest that well-defined nonpolar InGaN/GaN MQW-NWs can be utilized for the realization of high-performance LEDs.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1189-1192
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• 2006

We have demonstrated the novel technique for spacing two flexible substrates in stable by using rigid pillar spacer array and micro-contact printing assembling technique. Specially designed columnar structure generates self-collected adhesive polymer feature results in a good adhesion and a high mechanical stability to the external bending deformations.

• Transactions of Materials Processing
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• v.20 no.1
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• pp.60-63
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• 2011

BLU(back light unit) is one of kernel parts of LCD(liquid crystal display) unit. New 3-D micro-lens pattern for LGP(light guide plate), one of the most important parts of LCD-BLU, had been researched. Instead of dot pattern made by chemical etching or laser ablation, SCS(slanted curved surface) micro-lens pattern was designed with optical CAE simulation. This study introduce the method of design using optical CAE simulation for SCS micro-lens, the new fabrication method of micro-mold with SCS micro-lens pattern.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.26-31
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• 2001

Recently, miniaturization and mass production are the main trends in manufacturing fields. Therefore, ultraprecision machining and MEMS technology have been taken more and more important position in machining of microparts. Micro endmilling is one of the prominent technology that has wide spectrum of application field ranging from macro parts to micro products, such as PDP and IT components, in precision products manufacturing. However, the deburring is significant problem in making smooth and precise parts in micro endmilling. This paper shows removal characteristics of burr generated by micro endmilling process. Additionally, it is necessary to understand the formation mechanism of burr of micro barrier ribs to find proper deburring method.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.280-283
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• 2004

Micro-lens patterned micro-mold fabrication method for Light Guiding Plate(LGP), kernel part of LCD-BLU(Back Light Unit), was presented. Instead of erosion dot pattern for LGP optical design, micro-lens pattern, fabricated by LIGA-reflow process, was applied. Optical pattern design method was also developed not only for negative pattern LGP, but also positive pattern LGP. During injection molding process, experimental study was conducted to improve replication quality and brightness of ${\sim}50um$ micro-lens pattern mold. The effect of mold temperature for the replication quality of micro-lens array was studied.

• Journal of the Semiconductor & Display Technology
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• v.18 no.2
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• pp.6-10
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• 2019

In the presence of $\mu-tip$ for narrow stripe coating, there appears lateral capillary flow along the hydrophilic head lip because the $\mu-tip$ has some resistance to flow. It was known to be suppressed by increasing the contact angle of the head lip. In this paper, we have demonstrated by computational fluid dynamics(CFD) simulations that it can also be suppressed by the formation of micro-patterns on the shim and meniscus guide embedded into the slot-die head. To optimize the micro-patterned structure, we have performed simulations by varying the groove width, depth, and clearance. In the absence of micro-patterns, it is shown by experiment and simulation that the solution spreads to a distance of $1,300{\mu}m$ from the ${\mu}-tip$. In the presence of micro-patterns with the groove width and clearance of $50{\mu}m$, the distance the solution spreads is reduced to $260{\mu}m$. However, no further suppression in the capillary flow is observed with micro-patterns with the groove width of $40{\mu}m$ or less. It is also observed that the capillary flow is not affected by the groove depth if it is larger than $10{\mu}m$. We have shown that the distance the solution spreads can be reduced further to $204{\mu}m$ by coating a hydrophobic material (contact angle of $104^{\circ}$) on the surface of micro-patterns having the groove width and clearance of $50{\mu}m$.