• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.215-222
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• 2003

The new square electro-magnetic chuck, which is using for the clamping devices on a grinding machine, is developed in this study to improve the convenience of grinding works. The various kinds of structures are recommended to find the most adequate magnetic characteristics through the analytical approach using finite element methods. The analyzed results are retrofitted to solve the drawbacks of previous models step by step by considering the magnetic fields, strength and distribution of drag force, and thermal deformations of chuck. such as high parallelism and flatness. Finally the best recommended models is designed to satisfy the KS specifications required for the commercial magnetic chuck. The prototype chuck with this dimensions and structures is manufactured. For this final model, the experimental verifications are investigated whether the KS specifications are satisfied.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.3
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• pp.53-58
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• 2008

This study was conducted to evaluate the flatness of the porous type of dicing chuck. Two measurement systems for a vacuum chuck with a porous type of ceramic plate were prepared using a digital indicator and a laser interferometer. 6 inch of silicon and glass wafer were also used. Vacuum pressure from 100mmHg to 700mmHg by 100mmHg was increased. From experiments, chucked-wafer flatness was converged to the dicing chuck flatness itself even though the repeatability of contact method using indicator was unstable. Finally, the chuck flatness was estimated below $2{\mu}m$ with peak-to valley value.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.6
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• pp.8-15
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• 2005

The new square electro-magnetic chuck, which can be used for the clamping devices on a grinding machine, is developed in this study to improve the convenience of grinding works. The various kinds of structures are recommended to find the most adequate magnetic characteristics through the analytical approach using finite element methods. The analyzed results are retrofitted to solve the drawbacks of previous models step by step by considering the magnetic fields, strength and distribution of drag force, and thermal deformations of chuck such as high parallelism and flatness. Finally the best recommended models is designed to satisfy the KS specifications required fur the commercial magnetic chuck. The prototype chuck with this dimensions and structures is manufactured. For this final model, the experimental verifications are investigated whether the KS specifications are satisfied.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.6
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• pp.614-619
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• 2009

The STW(servo track writing) system which is the process of writing servo signals on disks before assembling in drives uses the spindle motor-chuck mechanism to realize low cost because the spindle motor-chuck mechanism has merit which can simultaneously write multi-disk by piling up disks in hub. Therefore, when the spindle motor-chuck mechanism of horizontal type operates in high rotation speed it is necessary to reduce the effect of RRO(repeatable run-out) and NRRO(non-repeatable run-out) to achieve the high precision accuracy of nano-meter level during the STW process. In this paper, we analyzed that the slip in assembly surfaces can be caused by the mechanical tolerance and clamping force in hub-chuck mechanism and can affect NRRO performance. We designed springs for centering and clamping considering centrifugal force by the rotation speed and assembly condition. The experimental result showed NRRO performance improves about 30 % than case of weak clamping force. The result shows that the optimal design of the spindle motor-chuck mechanism can effectively reduce the effect of NRRO and RRO in STW process.

• Journal of the Semiconductor & Display Technology
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• v.15 no.3
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• pp.72-77
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• 2016

As the semiconductor production technology has gradually developed and intra-market competition has grown fiercer, the caliber of Si Wafer for semiconductor production has increased as well. And semiconductors have become integrated with higher density. Presently the Si Wafer caliber has reached up to 450 mm and relevant production technology has been advanced together. Electrostatic chuck is an important device utilized not only for the Wafer transport and fixation but also for the heat treatment process based on plasma. To effectively control the high calories generated by plasma, it employs a refrigerant-based cooling method. Amid the enlarging Si Wafers and semiconductor device integration, effective temperature control is essential. Therefore, uniformed temperature distribution in the electrostatic chuck is a key factor determining its performance. In this study, the form of refrigerant flow channel will be investigated for uniformed temperature distribution in electrostatic chuck.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2572-2576
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• 2009

The wafer prober is used in mass production process of semiconductor chips. The chuck in wafer prober must have a uniform temperature distribution when the chuck is heated or cooled. The temperature distribution of prober chuck is measured by using a thermocouple when the chuck is cooled. The temperature distribution is also calculated by using a CFD program, FLUENT. The measured temperature and calculated temperature show similar distributions. A modified coolant circuit distribution for the improving temperature uniformity is suggested based on the numerical analysis results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.1-7
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• 2021

The deep learning image processing technique was used to prevent accidents in lathe work caused by worker negligence. During lathe operation, when the chuck is rotated, it is very dangerous if the operator's hand is near the chuck. However, if the chuck is stopped during operation, it is not dangerous for the operator's hand to be in close proximity to the chuck for workpiece measurement, chip removal or tool change. We used YOLO (You Only Look Once), a deep learning image processing program for object detection and classification. Lathe work images such as hand, chuck rotation and chuck stop are used for learning, object detection and classification. As a result of the experiment, object detection and class classification were performed with a success probability of over 80% at a confidence score 0.5. Thus, we conclude that the artificial intelligence deep learning image processing technique can be effective in preventing incidents resulting from worker negligence in future manufacturing systems.

• Journal of the Korean institute of surface engineering
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• v.44 no.4
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• pp.165-171
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• 2011

In this work, handling of sapphire substrate for LED by using an electrostatic chuck was studied. The electrostatic chuck consisted of alumina dielectric, which was doped with 1.2 wt% $TiO_2$. As the volume resistivity of alumina dielectric was decreased, the electrostatic force was increased by Johnsen-Rahbek effect. The narrower width and gap size of electrode led to the stronger electrostatic force. When alumina dielectric with $3.20{\times}10^{11}{\Omega}{\cdot}cm$ resistivity and 3 mm width/1.5 mm gap sized electrode was used, the strongest electrostatic force in this work was obtained, which value reached to ~14.46 gf/$cm^2$ at 2.5 kV for 4-inch sapphire substrate. This results show that alumina electrostatic chuck with low resistivity and fine electrode pattern is suitable for handling of sapphire substrate for LED.

• Journal of the Semiconductor & Display Technology
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• v.23 no.2
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• pp.12-18
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• 2024

A Electrostatic chuck is a device that fixes the substrate, using the force between charges applied between two parallel plates to attract substrates such as wafers or OLED panels. Unlike mechanical suction methods, which rely on physical fixation, this method utilizes the force of electrostatics for fixation, making it important to verify the adhesion force. As the size of the substrate increases, deformations due to gravity or chucking force also increase, and the adhesion force decreases rapidly as the distance between the chuck and the substrate increases. The outlook for displays is shifting from small to large OLEDs, necessitating consideration of substrate deformations. In this paper, to confirm the deformation of the substrate through various patterns, a simplified 2D model using Ansys' electromagnetic field analysis program, Maxwell, and the static structural analysis program, Mechanical, was utilized to observe changes in adhesion force according to the variation in the air gap between the substrate and the chuck. Additionally, the chucking force was analyzed for the size of the substrate, and the deformation of the substrate was confirmed when gravity and chucking force act simultaneously.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1645-1650
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• 2003

A numerical and experimental study is made of thermal behavior of a hot chuck which is specially designed for flip-chip bonders. The hot chuck consists of radiant heat sources and a heated plate of very high conductivity, which is for achievement of high-speed heat-up. A simplified numerical model is developed to simulate unsteady thermal behavior of the heated plate. Parallel experimental work is also conducted for a prototype of the hot chuck. Based on the experimental data, the numerical model is tuned to improve the reliability and accuracy. Design analysis using the numerical model is conducted. The results of numerical computations illustrate that the radiant heater system adopted in this study satisfies the key design requirements for a high-performance hot chuck.