• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.98-103
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• 2012

One of the problems in the grinding process using the machining center(MC) with a small diametric wheels is machining error due to decrease of the quill diameter. In this thesis, side-cut grinding is performed with a vitrified bonded CBN wheel on the machining center to establish the basis of the grinding using MC. The grinding force and machining error are investigated experimentally for the change of the machining condition. It is possible to estimate the machining performance by the ratio of the setting depth of cut and actual depth of cut. In addition, the relation between normal grinding force and machining error is presented by the experimental formula.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.1
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• pp.186-195
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• 2002

The mechanism of micro machining of reacted layer on silicon surface were proposed. The depth of reacted layer and the change of mechanical property were measured and analyzed. Depth of hydrated layer which is created on the surface of silicon by potassium hydrate was analyzed with SEM and XPS. The decrease of the micro victors hardness of silicon surface was shown with the increase of the concentration of potassium hydrate and the change of the dynamic friction coefficient by chemical reacted layer was measured due to the readiness of machining. The experiment of groove machining was done with 3-axis machine with constant load. With chemical mechanical micro machining the surface crack and burrs generated by both brittle and ductile micro machining were diminished. And the surface profile and groove depth was shown in accordance with the machining speed and reaction time with SEM and AFM.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.980-983
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• 2002

In micro-machining, diamond tool is commonly used because it brings much better micro-machinability due to its edge sharpness. However, it is a big question even how thinly the sharp edge of a diamond tool can cut a ship from the workpiece surface. This paper is to investigate the critical cutting depth, at which the dominant cutting mode changes from chip formation to burnishing or vice versa, for a given edge radius. The theoretically critical cutting depth is 0.25$\mu\textrm{m}$(0.8$\mu\textrm{m}$) in cutting using a square type(V-type) diamond tool that has edge radius of 1$\mu\textrm{m}$(1.5$\mu\textrm{m}$). Experimentally, the dominant cutting mode changes and cutting surface becomes better at critical cutting depth. To get high quality surface, depth of cut must be critical cutting depth because less plastically deformed substrate is left on the surface.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.410-413
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• 2005

There are technical requirements to manufacture large size functional parts with not only simple geometries like a flat or spherical surface but also sculptured geometries. In addition, the required machining accuracy for these parts is becoming more severe day-by-day. In general, the forms of machined parts are determined by relative position between the workpiece and the tool during cutting. To improve machining accuracy, the relative position error should be maintained within the required accuracy. This study deals with estimation and calibration of depth of cut using AE signal in micro-machining.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.6
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• pp.29-35
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• 2010

Recently the industry high-speed machining has been applied to the automotive, aircraft, electronics parts machining because the effect of cost savings, machining time reduction and productivity improvement. In this study recently the aircraft structural aluminum alloy 7075 used in cutting the ball end-mill on the surface roughness terms most affect the parameters of the spindle speed and feed rate on the surface roughness of the work-piece according to the cutting depth is to investigate. Cutting depth at 0.3 mm has the lowest surface roughness.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.126-133
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• 2002

The cutting thickness of ultra-precision machining is generally very small, only a few micrometer or even down to the order of a few nanometer. In such case, a basic understanding of the mechanism on the micro-machining process is is necessary to produce a high quality surface. When machining at very small depths of cut, metal flow near a rounded tool edge become important. In this paper a finite element analysis is presented to calculate the stagnation point on the tool edge or critical depth of cut below which no cutting occurs. From the simulation, the effects of the cutting speed on the critical depths of cut were calculated and discussed. Also the transition of the stagnation point according to the increase of the depths of cut was observed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.636-639
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• 2003

It is difficult to machine below 10 micrometers by conventional machining methods, such as micro-EDM. However, ultra micro machining using focused ion beam(FIB) is able to machine to 50 nanometers. In addition, 3 dimensional structures can be made by a combination of FIB and CVD to the level of 10 nanometers. Die ＆ moulds techniques are better than one-to-one machining techniques in the mass production of ultra size structures, in regards to production costs. In this case, the machining precision of die ＆ moulds affects produced parts. Also, it is advantageous to machine die ＆ moulds to the 10 micrometer level by FIB technique rather than other techniques. In this paper, the grooving characteristics for die ＆ mould materials by FIB were carried out experimentally in order to compare the machining characteristics of FIB with conventional machining methods. The results showed that the machining parameters and the scanning path of FIB affects the precision. The machined width and depth of the groove varied depending on the required depth due to the redeposition of the sputtered ion material accumulating on both the bottom and the side of the wall.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.3-7
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• 1995

Force generated during grinding process causes elastic defomation. The effect of this deforms a workpiecs. So grinding system is explainable using the concept of macining elasticity phenomenon. Machining elasticity is defined as ratio between the true depth of c ut, and an importnat factor to affect material removal mchanism and productivity. Generally, to produce accurate surface and dimensionally precise components operators depend on their experiences. Because of these, productivity is reduced and time is wasted. The objective of this reserch is to study the effect of grinding conditions, such as table speed, depth of cut on the machining elasticity parameter.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.7
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• pp.227-232
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• 2003

In order to make a deep and precise micro-hole, electrode wear and clearance between the electrode and the workpiece are important parameters using micro-electrical discharge machining. In this study, experiments were carried out to show the characteristics of electrode wear and radial clearance with respect to the depth of machined hole. Electrode wear varied with respect to the depth of hole. With deeper machined hole, bigger clearance was observed. Also it was found that the diameter of electrode influences machining characteristics of deep holes.

• Journal of the Semiconductor & Display Technology
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• v.20 no.1
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• pp.59-63
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• 2021

Upper electrode is one of core parts using plasma etching process at semiconductor. The purpose of this study is to analyze effects of cutting conditions for mechanical machining of silicon upper electrode. For this research, surface roughness of machined workpiece and depth of damage inside of silicon electrode are experimented and analyzed and different values of feed rate and depth of cut are applied for the experiments. From these experiments, it is verified that the surface roughness and internal damaged layer get worse according to take more fast feed rate. In conclusion, cutting condition is very important factor for machining. Results of this study can use to develop various parts which are made from single crystal silicon and affect various benefits to the semiconductor industry for better productivity.