• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.167-172
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• 2003

The machining method by using end-milling tool has been applying in machining structures of various shapes because of the availability. Recently, all kinds of industries based on the parts of micro shape are developing, and the demands of mechanical micro machining technology are Increasing suddenly to produce these parts. According to such changes, the technology of the micro end-milling machining is applying as one of the most important machining means. This research is to aim at developing machining technology for various micro structures using micro end-mill. This paper introduces micro mechanical machining system with ultra precision, and demonstrates methods manufacturing all sorts of parts and moldings for industry and examples of applicable machining by using micro end-milling tool of micro sizes from hundreds to tens in diameter.

• Transactions of Materials Processing
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• v.15 no.9 s.90
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• pp.673-678
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• 2006

Demands for micro parts have increased with recent advances in IT and machinery industries. However, the present technology loaves much to be desired to effectively produce parts with the volume of $1mm^{3}$ and less by mechanical method in large quantities. This paper provides a method for efficient quantity production of complete micro 3D structure using micro end-milling cutting process. The possibility has proven via manufacturing experiment of a multistage micro complex gear structure of $500{\mu}m$ in length, $500{\mu}m$ in maximum external diameter and a volume of $1mm^{3}$ and less.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.1
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• pp.31-36
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• 2009

Micro-machining technology has been adopted for shape accuracy of micrometer and sub-micrometer scale, surface roughness of tens nanometer in industries. In micro-machining process the quality of machined surface is derived from machining condition and tooling. This paper investigates AE(acoustic emission) and cutting force signals according to machined surface quality related to machining condition. Machined surface quality was analyzed by the AE and cutting force parameter which reflect surface morphology. The characteristics of signal were extracted for process optimization by monitoring both the tool condition and the machined surface texture in micro end milling process.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.198-204
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• 2007

This study was carried out to develope a flow control system using to supply PR(photo-resist) in the semi-conductor manufacturing process. The features of this system are to be able to measure the high viscosity and micro-flow. To meet above study object some ideas was induced to design a new concept valve with new material, multi-cross wheel, and new sealing method etc.. As the evaluations on the developed micro-flowmeter it was enough satisfied to use at the IT industries such as photo-resist process.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.5
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• pp.38-44
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• 2020

Surface texturing of micro-dimples has been used in many manufacturing industries to reduce friction between two sliding contacted surfaces. Surface texturing decreases the frictional force owing to minimizing of the sliding contact area. In this paper, micro-dimples have been fabricated on an Al6061-T6 surface using a two-frequency elliptical vibration texturing (TFEVT) method. A high-frequency of 18 kHz and low-frequency of 250 Hz were applied to an elliptically-vibrated tool holder. The Stribeck curve was plotted to analyze the friction coefficient trends. Furthermore, the representative wetting index, such as the water contact angle (WCA), was measured by considering the friction coefficient. WCA is associated with micro-dimple density and associated parameters. Consequently, the dimpled surfaces with a low friction coefficient exhibited a relatively high WCA in the feed direction. According to the Stribeck curve, the dimpled surfaces demonstrate superior friction performance for mixed-film lubrication compared to the non-textured surface.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.6
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• pp.13-24
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• 2017

The purpose of this study is to examine the effect of the management of receivables on the management performance of micro manufacturing industries. The results of the survey are as follows. First, among the factors of management of pre- and post-trade receivables in the micro manufacturing industries, management organization and regulations, contract execution management, bad debt control, which are the subordinate factors of credit control, are positive (+) significant effect on stability. In terms of profitability, management organizations and regulations, which are subordinate factors of credit control management, have a positive (+) significant effect on profitability. The recovery management, which is a factor of management of post - receivable receivables, did not have a significant effect on the stability and profitability of financial management performance. Second, the effect of financial performance on organizational satisfaction is positively related to stability, while profitability has no significant effect on organizational satisfaction. The implication of this study is that pre - trade receivables management is more important than post - trade receivables management in the management of accounts receivables of micro manufacturing industries. Proactive credit management refers to the procedure of establishing and managing personal guarantees and physical guarantees in order to smooth the execution of the obligations at the same time as the contract is concluded through processes such as credit investigation, analysis and evaluation, and sales decision before the contract is concluded. Post receivables management based on the assumption of default is a receivables management procedure from receipt of receivables that are already defaulted to bad debts to bad debt processing. If the collection of receivables is delayed or bad debt is increased, Furthermore, a corporation may be subject to bankruptcy risk (insolvency by paper profits). Therefore, it is meaningful that this study suggests direction to induce change of contract type in advance by understanding the possibility of settlement of accounts receivable and recovery of bad debts within the day of transition in case of contract of micro manufacturing industries.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.62-67
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• 2012

Recently UV laser is widely used to process micro parts using various materials such as polymers, metals and ceramics because it has a very high intensity at the focused spot area. It is generally known that there are still some difficulties for alumina($Al_2O_3$) ceramics to directly make micro patterns like holes and lines on the surface of working material using 355nm UV laser because the alumina has a very low absorption coefficient at that wavelength. But nowadays new alumna with nano-porous holes is developed and applied to advanced micro functional parts of IT, BT and BT industries. In this paper, we are going to show the mechanism of photo-thermal ablation for nano-porous ceramics. Inside hole there is a lot of multiple reflections along the depth of hole. Experimentally we can find the micro hole drilling and micro grooving on the surface of nano-porous alumina.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.275-280
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• 2001

Recently, the trends of industrial products grow more miniaturization, variety and mass production. Micro drilling which take high precision in cutting work is requested more micro hole and high speed working. Especially, Micro deep hole drilling is becoming more important in a wide spectrum of precision production industries, ranging from the production of automotive fuel injection nozzle, watch and camera parts, medical needles, and thick multi-layered Printed Circuit Boards(PCB) that are demanded for very high density electric circuitry. This paper shows the tool monitoring results of micro drill with tool dynamometer. And additionally, microscope with built-in monitor inspection show the relationship between burr in workpiece and chip form of micro drill machining.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.4
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• pp.20-27
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• 2009

The characteristics of titanium alloy as a relatively advanced material is low density, avirulent and, superior corrosive resistant, therefore the use of titanium alloy is increasing lately in aerospace and mechanical technologies, precision machinery, electronics industry, petro-chemical industries and biomedical areas. In these days, the titanium alloy product is required various surface qualities of not only smooth surface but also rough surface depending on usages. The purpose of this experimental research is to find the optimum surface roughness of titanium alloy of Ti-6Al-4V, by micro abrasive blasting as depending variable conditions of working pressure, nozzle size, working time, stand of distance and power particle size.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.1
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• pp.101-108
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• 2019

In this study, the hole-cavity resonance technology and the micro pore stainless chip sintering technology were fused to develop silencers with excellent noise attenuation performance even at fluid pressures exceeding 30 bar for the first time at home and abroad. As a result of this study, the noise attenuation performance was greatly improved as reflection, loss, and resonance were made to occur thousands of times simultaneously when fluids pass through the sintered micro pore stainless steel chip sound absorber. The noise of the gas emitted from the bomb without the silencer was shown to be 125dB. And noise test conducted after installation of the silencer showed the noise of 67dB. Given the study results, the amount of noise was greatly reduced in the sintered silencer.