• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.5
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• pp.75-80
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• 2015

Nowadays, flat-shaped cover glass is widely used for mobile devices. However, for its good design and convenience of use, curved cover glass has been demanded. Thus, many companies have tried to produce curved cover glass through the shaving technique, but the production efficiency is very low. Therefore, the molding technique has been adopted to increase the efficiency for the curved-glass production system. For a glass-molding system, several heating blocks are installed, and the flat cover glass is sequentially heated and molded. The production time for the cover glass is very different depending on the heating conditions; thus, the prediction of the production time for different heating conditions should be needed. Therefore, in this study, the computations were performed with different heating conditions (uniform and non-uniform) in the present cover glass-molding machine. For uniform and non-uniform heating conditions, the simple correlation between the heating time and the heater capacity and the heating time to achieve higher durability can be suggested, respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.4
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• pp.50-55
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• 2014

Currently, flat cover glasses are widely applied to mobile devices. However, for a good design and for convenience of use, curved cover glasses are in demand. Thus, many companies are attempting to produce curved cover glasses using a shaving technique, but the production efficiency is very low. Therefore, a molding technique has been adopted to increase the efficiency of curved glass production systems. For a glass molding system, a uniform temperature distribution of the mold is crucial to produce high-quality curved cover glasses. Before setting the heating conditions of the molding system for a uniform temperature distribution by a thermal analysis, verification is required. Therefore, in this study, temperature measurements were conducted for a prototype molding system and the experimental results were compared with simulation computations. The temperatures of the heating block surface were in good agreement with the computational results for transient and steady conditions.

• Journal of the Korean institute of surface engineering
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• v.52 no.6
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• pp.310-315
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• 2019

The use of a silicon carbide (SiC)-based composite ceramic layer for the mold of a curved cover glass was demonstrated. The stress of SiC/VDR/graphite-based mold structure was evaluated via finite element analysis. The results revealed that the maximum tensile stress primarly occured at the edge region. Moreover, the stress can be reduced by employing a relatively thick SiC coating layer and, therefore, layers of various thicknesses were deposited by means of chemical vapor deposition. During growth of the layer, the orientation of the facets comprising the SiC grain became dominant with additional intense SiC(220) and SiC(004). However, the roughness of the SiC layer increased with increasing thickness of the layer and. Hence, the thickness of the SiC layer needs to be adjusted by values lower than the tolerance band of the curved cover glass mold.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.6
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• pp.36-42
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• 2020

Nowadays, the touch screen panel (TSP) cover glass for mobile smart devices is being developed with a curved glass shape due to different design requirements. Because the sizes of mobile smart devices continue to increase, there has also been a great increase in the demand for large-area curved glass greater than 20 inches. In this study, heat and fluid flow analysis using CFD was performed to optimize the heating surface temperature distribution of the large curved glass formation system. Five cooling water flow paths in the cooling block were designed and analyzed for each case. A function that can quantitatively calculate the temperature uniformity of the heating surface was proposed and these values were obtained for the five models. The temperature distributions of the heating surface and the energy consumption of the heating system were also compared and comprehensively analyzed. Based on the analysis results of the five different cooling channel path models, the optimal path design could be presented.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.51-55
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• 2021

With the recent development of various smartphone designs in the smartphone market, the use of curved cover glass has been required, and interest in curved glass production has increased. In this paper, we designed a pressurization system that simplified the size of the system using a wedge amplification mechanism for smartphone curved glass molding systems. The pressurization system consisted of a linear motor, a wedge, and a force sensor. The wedge was used to amplify the force, and the piezoelectric sensor was used to measure the force. In addition, the proposed amplification mechanism was confirmed to have an error of 1.27% through an experiment compared to the simulation, and the pressurization error of 0.76% for the pressurization profile 3,500N was verified through an experiment.