• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1179-1180
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• 2005

3D micro scaled shapes are fabricated with the method of direct writing and superposing grooving in ambient air using femto-second laser pulses and copper, aiming at establishing an industrially useful femto-second laser processing machine to be able to fabricate three dimensional micro-scale structures, especially micro scaled molds, and processing techniques. For the several advantages, there is no thermally influenced region around the area irradiated by the laser beam and surfaces irradiated laser beam are smooth and substances ablated to form are no attached on the surface of works and so on, the femto-second laser technology is anticipated for advanced micro/nano precision technology.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.106-111
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• 2004

Micro-stereolithography technology has made it possible to fabricate any form of three-dimensional microstructures. It makes a 3D structure by dividing the shape into many slices of relevant thickness along horizontal surface, hardening each layer of slice with a laser, and stacking them up to a desired shape. Until now, however, the micro-stereolithography device was not designed systematically because the key factors governing the device were not considered. In this paper, we designed micro-stereolithography device using axiomatic approach. This paper contains an overview and an analysis of a new proposed system for development of micro-stereolithegraphy device, and detailed descriptions of the activities in this system. The newly designed system offers reduced machine size by minimizing of optical components and decoupled design matrix.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.2
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• pp.78-83
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• 2007

In this paper, the digital model of the micro-factory has been established, inspected and evaluated by progress of assembly, manipulation and examination. The new paradigm of the system analysis is realized by digital simulation of the factory. The digital manufacturing system of the micro-factory was simulated through UML(Unified Modeling Language) with the object-oriented logical model analysis method and then the micro lens module assembly system was simulated with MST(Micro System Technology) Application Module.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.17-24
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• 2004

Surrface texturing of tribological application is another attractive technology of friction reducing. Also, reduction of friction is therefore considered to be a necessary requirement for improved efficiency of machine. In this paper attempts to investigate the effect of density for micro-scale dimple pattern using photolithography on bearing steel flat mated with pin-on-disk. We demonstrated the lubrication mechanism for a Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter for lubrication condition. It is found that friction coefficient is depended on the density of surface pattern. It was thus verified that micro-scale dimple could affect the friction reduction considerably under mixed and hydrodynamic lubrication conditions from based on friction map. Lubrication condition regime has an influence on the friction coefficient induced the density of micro dimple.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.368-368
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• 2006

Micro-molded parts can be defined as parts with microgram weight, parts with micro-structured surface, and parts with micro-precision. In this study, various micro-scale molded parts for various polymers were produced by using a precision micro-molding machine. Molded parts with nano-structure surface were also produced to analyze the effect of molding conditions on replication of surface pattern and higher-order structure development of molded parts. Replication of molded parts was influenced by material properties, molding conditions and size of surface pattern. Higher-order structure of molded parts was investigated by using polarized microscope. Skin-shear-core regions inside the molded parts were observed and shear region affected to surface replication.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.4
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• pp.1-7
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• 2010

Recently optical and electric and electronic forms in the field of ultra fine patterns has been used extensively, and techniques of the optical parts are required that can precision-machine this micro-patterns such as V or R-shaped micro-groove patterns. In this study, V and R type, shaping the way micro groove brass machining process to characterize the material feed rate and cutting depth and the V and R as a variable brother, using two kinds of diamond tools for each picture shape and surface roughness caused by conditions such as chips, processed through the analysis of effects of geometry and analysis such as precision machining.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.287-293
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• 2001

Resently, reduction of industrial products in size and weight has increased by the application of micro-drill for gadgets of high precision and gave rise to a great interest in a micro-drilling. Due to the lack of tool stiffness and the chip Packing, micro-drilling requires not only the robust tool structure which has not affected by the vibration, but also the effective drilling methods designed to prevent tool fracture from cutting troubles. Firstly, this paper presents a new manufacturing process of micro-drill for improving the Product rate and an optimum shape of micro-drill for lengthening the tool life, and secondly between tool life and drilling torque acquired in the inprocess monitoring system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.371-376
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• 1997

A 100*100.mu.m$^{2}$ aluminum micro mirror is designed and fabricated using a thick photoresist as a sacrificial layer andas a mold for nickel electroplating. The micro mirror is composed of aluminum mirror plate, two nickel support posts, two aluminum hinges, two address eletrodes, and two landing electrodes. The aluminum mirror plate,which is supported by two nickel support posts, is overhung about 10.mu.m from the silicon substrate. THe aluminum mirror plate is actuated like a seesaw by electrostatic force generated by electic potential difference applied between the mirror plate and the address electrode. This paper presents some methods to measure the optical and the dynamic characteristics of the fabricated micro mirror.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.1
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• pp.82-88
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• 2009

Ultra-precision turning is highly needed to manufacture molds for precision lens. In this study, micro-turning combined with elliptical vibration cutting (EVC), which is known to enhance micro- machining quality, was investigated by installing a rotary stage into the micro-grooving machine. From machining experiments involving materials of copper, brass, and aluminum and single and poly crystalline diamond tools, it was found that EVC produced thinner and curlier chips and that better surface finish could be achieved, compared with conventional turning, owing to prohibition of formation of burrs and built-up edges. Therefore, we found EVC micro turning could be readily utilized to manufacture precision mold.

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.204-211
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• 1994

Micro array lens systems are designed for a faximile or copy machine. The array type is hexagonal. Diameter of a lens is 0.16 mm and the distance of the center of the nearest neighbor is 0.192 mm. The magnitude of the lens system is 1:1. Working distane is 10.55 mm and the spot size is less than 0.04 mm radius on axis and 0.20 mm off-axis in case of single layer system. Working distance is 7.90 mm and the spot size is less than 0.07 mm radius on axis and 0.09 mm radius off axis in case of double layer system. Performance of single layer micro array lens system and double layer micro array lens system are compared with the characteristics of the ray fans.y fans.